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Ahern, ALM, Gómez-Gutiérrez J, Aburto-Oropeza O, Saldierna-Martínez RJ, Johnson AF, Harada AE, Sánchez-Uvera AR, Erisman B, Castro Arvizú DI, Burton RS.  2018.  DNA sequencing of fish eggs and larvae reveals high species diversity and seasonal changes in spawning activity in the southeastern Gulf of California. Marine Ecology Progress Series. 592:159-179. AbstractWebsite

ABSTRACT: Ichthyoplankton studies can provide valuable information on the species richness and spawning activity of fishes, complementing estimations done using trawls and diver surveys. Zooplankton samples were collected weekly between January and December 2014 in Cabo Pulmo National Park, Gulf of California, Mexico (n = 48). Ichthyoplankton is difficult to identify morphologically; therefore the DNA barcoding method was employed to identify 4388 specimens, resulting in 157 operational taxonomic units (OTUs) corresponding to species. Scarus sp., Halichoeres dispilus, Xyrichtys mundiceps, Euthynnus lineatus, Ammodytoides gilli, Synodus lacertinus, Etrumeus acuminatus, Chanos chanos, Haemulon flaviguttatum and Vinciguerria lucetia were the most abundant and frequent species recorded. Noteworthy species identified include rare mesopelagic species such as the giant oarfish Regalecus glesne and highly migratory and commercially important species such as black skipjack Euthynnus lineatus and yellowfin tuna Thunnus albacares. Spawning activities showed distinct seasonal patterns, with the highest abundance of ichthyoplankton recorded during spring, highest species richness during summer (90 OTUs) and lowest species richness during winter (28 OTUs). A total of 7 OTUs were recorded throughout the year (4.5%), 10 OTUs during 3 seasons (6.5%), 36 OTUs in 2 seasons (23%) and 104 OTUs were recorded in 1 season (66%). The study found eggs and/or larvae of 47 species that were not previously reported in Cabo Pulmo National Park. The results will allow resource managers to compare shifting populations and spawning patterns of species that may be affected by both conservation efforts and broader oceanographic changes associated with climate change.

Cota-Nieto, JJ, Erisman B, Aburto-Oropeza O, Moreno-Baez M, Hinojosa-Arango G, Johnson AF.  2018.  Participatory management in a small-scale coastal fishery-Punta Abreojos, Pacific coast of Baja California Sur, Mexico. Regional Studies in Marine Science. 18:68-79.   10.1016/j.rsma.2017.12.014   AbstractWebsite

We describe the structure and historic landings of the Punta Abreojos fishing cooperative (Baja California Sur, Mexico) for the period between 2001 and 2015 to understand the dynamics of an economically and ecologically successful coastal fishing community according to catches and the direct income of fishers. A total of 21 commercial species were classified into three major groups: cultural resources, target resources and complementary resources. The most important resource in terms of total biomass was Paralabrax nebulifer (58.4%), followed by Panulirus interruptus and P. inflatus (13.6%). Seriola lalandi, Atractoscion nobilis, Caulolatilus princeps, Paralichtys californicus and P. woolmani made up minor proportions of the total biomass contributing 7.0%, 5.7%, 3.4% and 3.2% respectively. Haliotis fulgens and H. corrugata represented just 1.1% of the total biomass caught. Lobsters were the most profitable source of direct income for fisherman (77.5%), followed by the green and pink abalone (10.4%), barred sand bass (5.6%), white seabass (2.7%), California and speckled flounder (1.2%), yellowtail (1%) and whitefish (0.4%). The rest of the catch was composed of six species of finfish that represented 4.1% of the total catch biomass and 0.4% of the revenues from fishing. This work provides a first clear base-line description of the fisheries in Punta Abreojos which implements a management program that aims to ensure the wellbeing of the fishers and the fishery. The cooperative has been successful in maintaining catch at levels considered optimal to sustain revenues and continued annual landings. A management and cooperative structure that allows for adaptive change whilst maintaining revenues of the fishers is testament to the stewardship of the community and the participatory management upon which the community is built. For this reason, Punta Abreojos should be considered an example of a successful small-scale fishing cooperative that other, less successful fishing groups, can learn from. (C) 2018 Elsevier B.V. All rights reserved.

Aburto-Oropeza, O, Lopez-Sagastegui C, Moreno-Baez M, Mascarenas-Osorio I, Jimenez-Esquivel V, Johnson AF, Erisman B.  2018.  Endangered species, ecosystem integrity, and human livelihoods. Conservation Letters. 11   10.1111/conl.12358   AbstractWebsite

If efforts to conserve endangered species lack long-term visions and neglect the human dimensions, conservation success will be questionable. Exclusion of stakeholders in decisions can lead to mistrust and polarization of groups. The story of the vaquita marina (Phocoena sinus) in the Upper Gulf of California provides a unique opportunity to discuss this paradigm. A proposed gear-switch in the regional fisheries addresses the bycatch issue that threatens the vaquita but neglects livelihoods, the traditions and heritage of the community, and the ecological integrity of the area, and it increases dependence on fishing subsidies. We estimate that it will cost an additional US $8.5 million (2/3 of the net revenue produced by gillnets and 30% more in fuel consumption) if local revenues are to be maintained at pregear-switch levels. Additionally, suggested new trawl gears caught 2.7 times more unusable (therefore discarded) bycatch than gillnets, which included invertebrates and small juvenile fishes of economically valuable and endangered species. Our results show that the proposed gear switch intervention can be considered another "quick-fix" intervention in the history of the vaquita conservation agenda that urgently needs long-term goals that adequately incorporate ecological, economic, and human well-being.

Egerton, JP, Johnson AF, Turner J, Le Vay L, Mascarenas-Osorio I, Aburto-Oropeza O.  2018.  Hydroacoustics as a tool to examine the effects of Marine Protected Areas and habitat type on marine fish communities. Scientific Reports. 8   10.1038/s41598-017-18353-3   AbstractWebsite

Hydroacoustic technologies are widely used in fisheries research but few studies have used them to examine the effects of Marine Protected Areas (MPAs). We evaluate the efficacy of hydroacoustics to examine the effects of closure to fishing and habitat type on fish populations in the Cabo Pulmo National Park (CPNP), Mexico, and compare these methods to Underwater Visual Censuses (UVC). Fish density, biomass and size were all significantly higher inside the CPNP (299%, 144% and 52% respectively) than outside in non-MPA control areas. These values were much higher when only accounting for the reefs within the CPNP (4715%, 6970% and 97% respectively) highlighting the importance of both habitat complexity and protection from fishing for fish populations. Acoustic estimates of fish biomass over reef-specific sites did not differ significantly from those estimated using UVC data, although acoustic densities were less due to higher numbers of small fish recorded by UVC. There is thus considerable merit in nesting UVC surveys, also providing species information, within hydroacoustic surveys. This study is a valuable starting point in demonstrating the utility of hydroacoustics to assess the effects of coastal MPAs on fish populations, something that has been underutilised in MPA design, formation and management.

Galland, GR, Erisman B, Aburto-Oropeza O, Hastings PA.  2017.  Contribution of cryptobenthic fishes to estimating community dynamics of sub-tropical reefs. Marine Ecology Progress Series. 584:175-184.   10.3354/meps12364   Abstract

ABSTRACT: Small, cryptic (cryptobenthic) fishes are an under-surveyed component of reef fish assemblages that can account for a significant amount of diversity, function, and structure of reef fish communities. A complete picture of reef fish dynamics requires an accounting of these species and inclusion of them in analyses of community ecology. We report the results of a large-scale, quantitative study of the rocky reef fish community in the Gulf of California (GOC), where we collected cryptobenthic fishes and surveyed conspicuous fishes to calculate species richness, density, biomass, and community metabolism of the entire fish assemblage. We catalogued 20764 individuals, representing 112 species in 36 families. Cryptobenthic fishes accounted for more than 40% on average of the species richness per site but were generally unobserved during visual surveys. They also accounted for more than 95% of the total fish abundance and up to 56% of the fish community metabolic requirement, both a likely result of their small body size. The relative contribution of cryptobenthic fishes to the entire quantitatively sampled assemblage differed between the northern and southern GOC, with the north being relatively ‘more cryptobenthic’ than the south. This study is the first to combine quantitative surveys and collections of the entire fish assemblage in the GOC and is one of the most extensive of its kind for any ocean basin, to date. Our results demonstrate the importance of quantifying all size classes and all functional groups when studying the ecology of diverse vertebrate communities.

Erauskin-Extramiana, M, Herzka SZ, Hinojosa-Arango G, Aburto-Oropeza O.  2017.  An interdisciplinary approach to evaluate the status of large-bodied Serranid fisheries: The case of Magdalena-Almejas Bay lagoon complex, Baja California Sur, Mexico. Ocean & Coastal Management. 145:21-34.   10.1016/j.ocecoaman.2017.05.005   AbstractWebsite

Groupers are an important part of the world-wide catch of finfish and are of great importance to artisanal and sport fisheries. Their biological characteristics, including very large size, slow growth, longevity, late age-at-maturity and the tendency to form spawning aggregations makes them particularly vulnerable to overfishing. In Baja California, Mexico, the lack of robust historical catch data and fishery independent estimates of abundance hinders the assessment of temporal trends in population size and the evaluation of grouper population dynamics, as well the development and implementation of adequate management plans. Using an interdisciplinary approach that included (1) the review of non-scientific historical documents, (2) analysis of official catch records, (3) interviews with three generations of fishermen and (4) visual censuses to estimate abundance and the current size distribution, we reconstructed the historical abundance and maximum sizes of six species of Serranids of the genera Epinephelus and Mycteroperca as well as Stereolepis gigas in the Magdalena-Almejas Bay lagoonal complex in northwestern Mexico. Although catch volumes increased by 225% during the last 13 years, fishermen perception indicated a 30% decrease in the estimated maximum size and 57% decrease in the maximum weight captured over the past four decades. Based on insight gained from the four approaches, the general trend suggested an overall decrease in the abundance of some species. However, these changes were not perceived equally by the three generations of interviewed fishers; only older fishermen (>55 years of age) perceived a drastic decrease in population size. It is therefore important to involve young fishers in educational programs to avoid incurring in a shifting baseline syndrome. The limited quantitative data available for the region coupled with a trend toward lower abundance and smaller maximum sizes makes the implementation of specific monitoring and management measures for these species imperative. (C) 2017 Elsevier Ltd. All rights reserved.

Rowell, TJ, Demer DA, Aburto-Oropeza O, Cota-Nieto JJ, Hyde JR, Erisman BE.  2017.  Estimating fish abundance at spawning aggregations from courtship sound levels. Scientific Reports. 7:3340.   10.1038/s41598-017-03383-8   Abstract

Sound produced by fish spawning aggregations (FSAs) permits the use of passive acoustic methods to identify the timing and location of spawning. However, difficulties in relating sound levels to abundance have impeded the use of passive acoustics to conduct quantitative assessments of biomass. Here we show that models of measured fish sound production versus independently measured fish density can be generated to estimate abundance and biomass from sound levels at FSAs. We compared sound levels produced by spawning Gulf Corvina (Cynoscion othonopterus) with simultaneous measurements of density from active acoustic surveys in the Colorado River Delta, Mexico. During the formation of FSAs, we estimated peak abundance at 1.53 to 1.55 million fish, which equated to a biomass of 2,133 to 2,145 metric tons. Sound levels ranged from 0.02 to 12,738 Pa2, with larger measurements observed on outgoing tides. The relationship between sound levels and densities was variable across the duration of surveys but stabilized during the peak spawning period after high tide to produce a linear relationship. Our results support the use of active acoustic methods to estimate density, abundance, and biomass of fish at FSAs; using appropriately scaled empirical relationships, sound levels can be used to infer these estimates.

Aburto-Oropeza, O, Leslie HM, Mack-Crane A, Nagavarapu S, Reddy SMW, Sievanen L.  2017.  Property Rights for Fishing Cooperatives: How (and How Well) Do They Work? World Bank Economic Review. 31:295-328.   10.1093/wber/lhw001   AbstractWebsite

Devolving property rights to local institutions has emerged as a compelling management strategy for natural resource management in developing countries. The use of property rights among fishing cooperatives operating in Mexico's Gulf of California provides a compelling setting for theoretical and empirical analysis. A dynamic theoretical model demonstrates how fishing cooperatives' management choices are shaped by the presence of property rights, the mobility of resources, and predictable environmental fluctuations. More aggressive management comes in the form of the cooperative leadership paying lower prices to cooperative members for their catch, as lower prices disincentivize fishing effort. The model's implications are empirically tested using three years of daily logbook data on prices and catches for three cooperatives from the Gulf of California. One cooperative enjoys property rights while the other two do not. There is empirical evidence in support of the model: compared to the other cooperatives, the cooperative with strong property rights pays members a lower price, pays especially lower prices for less mobile species, and decreases prices when environmental fluctuations cause population growth rates to fall. The results from this case study demonstrate the viability of cooperative management of resources but also point toward quantitatively important limitations created by the mismatch between the scale of a property right and the scale of a resource.

Erisman, BE, Cota-Nieto JJ, Moreno-Baez M, Aburto-Oropeza O.  2017.  Vulnerability of spawning aggregations of a coastal marine fish to a small-scale fishery. Marine Biology. 164   10.1007/s00227-017-3135-8   AbstractWebsite

For marine fishes that form spawning aggregations, vulnerability to aggregation fishing is influenced by interactions between the spatio-temporal patterns of spawning and aspects of the fishery that determine fishing effort, catch, and catch rate in relation to spawning. We investigated the spatio-temporal dynamics of spawning and fishing for the barred sand bass, Paralabrax nebulifer, in Punta Abreojos, Mexico from 2010 to 2012 as a means to assess its vulnerability to aggregation fishing by the local commercial fishery. Monthly, spatial patterns in gonadal development in collected females indicated that adults formed spawning aggregations at two sites in Punta Abreojos during July and August. Monthly patterns in the spatial distribution of fishing matched the spawning behavior of P. nebulifer, with effort and catch concentrated at spawning aggregation sites during those months. However, fishing effort, catch, and catch-per-unit effort did not increase during the spawning season, and fishing activities associated with the spawning season comprised only a small percentage of the total annual effort (22%) and catch (17%).Therefore, while the population of P. nebulifer at Punta Abreojos should be vulnerable to aggregation fishing due to the spatio-temporal dynamics of its spawning aggregations, vulnerability is greatly reduced, because fishing activities are not disproportionately focused on spawning aggregations and fishing methods are not optimized to maximize harvest from the aggregations. Differences between our results and previous studies on aggregation fisheries for P. nebulifer in California, USA, reinforce the importance of assessing factors influencing vulnerability to aggregation fishing at regional scales for prioritizing management efforts.

Rubio-Cisneros, NT, Aburto-Oropeza O, Jackson J, Ezcurra E.  2017.  Coastal Exploitation Throughout Marismas Nacionales Wetlands in Northwest Mexico. Tropical Conservation Science. 10   10.1177/1940082917697261   AbstractWebsite

The consequences of human exploitation on wetlands remain unresolved for many regions. Marismas Nacionales wetland in Northwest Mexico is a Ramsar site and a Biosphere Reserve at Mexico. By integrating literature sources, fisheries data, and field studies, this study shows how long-term coastal exploitation has contributed to subsequent declines in fishery resources and the wetland health. Oysters declined in prehistoric times and potentially recovered during the Spanish occupation. Further, overexploitation of oyster banks in the mid-19th century diminished oysters' populations by early 20th century. Then, inshore fishing cooperatives flourished and exploited shrimp and finfish. These fisheries seemed sustainable until outboard motors and nylon nets populated estuaries. Government subsidies and free-market policies of late 20th century exacerbated fishing effort and disrupted social organization of fishing cooperatives which lead to widespread illegal and unsustainable fishing practices. Currently, the seemingly subtle shifts in artisanal fishing techniques have modified Marismas' food webs. These results can help develop conservation guidelines for wetlands ecosystem services and be a reference for managers in other countries where long-term data of wetlands exploitation is limited.

Johnson, AF, Moreno-Baez M, Giron-Nava A, Corominas J, Erisman B, Ezcurra E, Aburto-Oropeza O.  2017.  A spatial method to calculate small-scale fisheries effort in data poor scenarios. Plos One. 12   10.1371/journal.pone.0174064   AbstractWebsite

To gauge the collateral impacts of fishing we must know where fishing boats operate and how much they fish. Although small-scale fisheries land approximately the same amount of fish for human consumption as industrial fleets globally, methods of estimating their fishing effort are comparatively poor. We present an accessible, spatial method of calculating the effort of small-scale fisheries based on two simple measures that are available, or at least easily estimated, in even the most data-poor fisheries: the number of boats and the local coastal human population. We illustrate the method using a small-scale fisheries case study from the Gulf of California, Mexico, and show that our measure of Predicted Fishing Effort (PFE), measured as the number of boats operating in a given area per day adjusted by the number of people in local coastal populations, can accurately predict fisheries landings in the Gulf. Comparing our values of PFE to commercial fishery landings throughout the Gulf also indicates that the current number of small-scale fishing boats in the Gulf is approximately double what is required to land theoretical maximum fish biomass. Our method is fishery-type independent and can be used to quantitatively evaluate the efficacy of growth in small-scale fisheries. This new method provides an important first step towards estimating the fishing effort of small-scale fleets globally.

Erisman, B, Heyman W, Kobara S, Ezer T, Pittman S, Aburto-Oropeza O, Nemeth RS.  2017.  Fish spawning aggregations: where well-placed management actions can yield big benefits for fisheries and conservation. Fish and Fisheries. 18:128-144.   10.1111/faf.12132   AbstractWebsite

Marine ecosystem management has traditionally been divided between fisheries management and biodiversity conservation approaches, and the merging of these disparate agendas has proven difficult. Here, we offer a pathway that can unite fishers, scientists, resource managers and conservationists towards a single vision for some areas of the ocean where small investments in management can offer disproportionately large benefits to fisheries and biodiversity conservation. Specifically, we provide a series of evidenced-based arguments that support an urgent need to recognize fish spawning aggregations (FSAs) as a focal point for fisheries management and conservation on a global scale, with a particular emphasis placed on the protection of multispecies FSA sites. We illustrate that these sites serve as productivity hotspots - small areas of the ocean that are dictated by the interactions between physical forces and geomorphology, attract multiple species to reproduce in large numbers and support food web dynamics, ecosystem health and robust fisheries. FSAs are comparable in vulnerability, importance and magnificence to breeding aggregations of seabirds, sea turtles and whales yet they receive insufficient attention and are declining worldwide. Numerous case-studies confirm that protected aggregations do recover to benefit fisheries through increases in fish biomass, catch rates and larval recruitment at fished sites. The small size and spatio-temporal predictability of FSAs allow monitoring, assessment and enforcement to be scaled down while benefits of protection scale up to entire populations. Fishers intuitively understand the linkages between protecting FSAs and healthy fisheries and thus tend to support their protection.

Stewart, JD, Beale CS, Fernando D, Sianipar AB, Burton RS, Semmens BX, Aburto-Oropeza O.  2016.  Spatial ecology and conservation of Manta birostris in the Indo-Pacific. Biological Conservation. 200:178-183.   10.1016/j.biocon.2016.05.016   AbstractWebsite

Information on the movements and population connectivity of the oceanic manta ray (Manta birostris) is scarce. The species has been anecdotally classified as a highly migratory species based on the pelagic habitats it often occupies, and migratory behavior exhibited by similar species. As a result, in the absence of ecological data, population declines in oceanic manta have been addressed primarily with international-scale management and conservation efforts. Using a combination of satellite telemetry, stable isotope and genetic analyses we demonstrate that, contrary to previous assumptions, the species appears to exhibit restricted movements and fine scale population structure. M. birostris tagged at four sites in the Indo-Pacific exhibited no long-range migratory movements and had non-overlapping geographic ranges. Using genetic and isotopic analysis, we demonstrate that the observed movements and population structure persist on multi-year and generational time scales. These data provide the first insights into the long-term movements and population structure of oceanic manta rays, and suggest that bottom-up, local or regional approaches to managing oceanic mantas could prove more effective than existing, international-scale management strategies. This case study highlights the importance of matching the scales at which management and relevant ecological processes occur to facilitate the effective conservation of threatened species. (C) 2016 Elsevier Ltd. All rights reserved.

Ulate, K, Sanchez C, Sanchez-Rodriguez A, Alonso D, Aburto-Oropeza O, Huato-Soberanis L.  2016.  Latitudinal regionalization of epibenthic macroinvertebrate communities on rocky reefs in the Gulf of California. Marine Biology Research. 12:389-401.   10.1080/17451000.2016.1143105   AbstractWebsite

We report on a latitudinal pattern in the structure and species composition of epibenthic macroinvertebrate communities on rocky reefs along a gradient of eight degrees of latitude in the Gulf of California. We provide quantitative evidence of a prominent shift in the taxa dominating these communities, particularly the sessile taxa (Cnidaria, Bivalvia, Annelida, Ascidiacea and Porifera). This pattern was not found in non-sessile taxa (Echinodermata, Decapoda, Cephalopoda, Gastropoda and Polycladida). Based on Bray-Curtis similarity and indicator species analysis we found that the macroinvertebrates of rocky reefs in the Gulf of California are distributed in three broad regions, indicating that sessile taxa are creating such a structure and are related to environmental changes tied to latitude. The northern region (>28 degrees N) was a temperate zone with the coolest water in winter and highest chlorophyll a concentrations, where Octocorallia of the genus Muricea were the dominant taxa. The central region (similar to 24-28 degrees N) had a mix of oceanographic features of the northern and southern regions and was dominated by Echinodermata in terms of species richness and density. The southern region (<24 degrees N) is a subtropical zone with typically warm and clear water, and dominated by Hexacorallia (stony corals). The southern area was less diverse and had lower densities than the central and northern areas. These three communities correspond to known oceanographic discontinuities in the Gulf of California. This implies that future coastal management plans and conservation efforts in the Gulf of California must be regionalized to support their distinct ecological communities.

Ezcurra, P, Ezcurra E, Garcillán PP, Costa MT, Aburto-Oropeza O.  2016.  Coastal landforms and accumulation of mangrove peat increase carbon sequestration and storage. Proceedings of the National Academy of Sciences.   10.1073/pnas.1519774113   Abstract

Given their relatively small area, mangroves and their organic sediments are of disproportionate importance to global carbon sequestration and carbon storage. Peat deposition and preservation allows some mangroves to accrete vertically and keep pace with sea-level rise by growing on their own root remains. In this study we show that mangroves in desert inlets in the coasts of the Baja California have been accumulating root peat for nearly 2,000 y and harbor a belowground carbon content of 900–34,00 Mg C/ha, with an average value of 1,130 (± 128) Mg C/ha, and a belowground carbon accumulation similar to that found under some of the tallest tropical mangroves in the Mexican Pacific coast. The depth–age curve for the mangrove sediments of Baja California indicates that sea level in the peninsula has been rising at a mean rate of 0.70 mm/y (± 0.07) during the last 17 centuries, a value similar to the rates of sea-level rise estimated for the Caribbean during a comparable period. By accreting on their own accumulated peat, these desert mangroves store large amounts of carbon in their sediments. We estimate that mangroves and halophyte scrubs in Mexico’s arid northwest, with less than 1% of the terrestrial area, store in their belowground sediments around 28% of the total belowground carbon pool of the whole region.

Rubio-Cisneros, NT, Aburto-Oropeza O, Ezcurra E.  2016.  Small-scale fisheries of lagoon estuarine complexes in Northwest Mexico. Tropical Conservation Science. 9:78-134. AbstractWebsite

Small-scale fisheries of lagoon-estuarine complexes (LECs) in Northwest Mexico were investigated using official landings data. Species groups found in landings were clustered into three categories according to their life cycle and habitat distribution: Lagoon-estuarine (LE), Transition zone (TZ) and Coastal (CO). Average landings were highest for LE (19,606 t yr(-1)), followed by TZ (7,234 t yr(-1)), and CO (3,155 t yr(-1)). In contrast, the total number of fished species groups had an opposite pattern: LE, TZ, and CO bore 31, 66 and 74 species groups respectively. The number of species groups in LE category significantly increased towards LECs of southern latitudes. The families with highest landings in LECs were Penaeidae, Portunidae, Mugilidae, Scombridae, and Lutjanidae. The area of LECs was significantly correlated with the amount of landings recorded for LE category. A similarity analysis of LECs species groups revealed a latitudinal clustering of northern and southern LECs. Overall, fisheries in LECs produced millions of $US per year, which support socioeconomic activities at the local, regional, and national scale. Although the information and landings data on LECs fisheries in Northwest Mexico have limitations for data analysis, our results suggest that changes in fisheries management of LECs, such as bottom-up management actions where resource users can participate, could help establish more sustainable fishing practices in these ecosystems and allow coastal communities to continue obtaining economic benefits and food supply from LECs in Northwest Mexico.

Aburto-Oropeza, O, Ezcurra E, Moxley J, Sanchez-Rodriguez A, Mascarenas-Osorio I, Sanchez-Ortiz C, Erisman B, Ricketts T.  2015.  A framework to assess the health of rocky reefs linking geomorphology, community assemblage, and fish biomass. Ecological Indicators. 52:353-361.   10.1016/j.ecolind.2014.12.006   AbstractWebsite

The recovery of historic community assemblages on reefs is a primary objective for the management of marine ecosystems. Working under the overall hypothesis that, as fishing pressure increases, the abundance in upper trophic levels decreases followed by intermediate levels, we develop an index that characterizes the comparative health of rocky reefs. Using underwater visual transects to sample rocky reefs in the Gulf of California, Mexico, we sampled 147 reefs across 1200 km to test this reef health index (IRH). Five-indicators described 88% of the variation among the reefs along this fishing-intensity gradient: the biomass of piscivores and carnivores were positively associated with reef health; while the relative abundances of zooplanktivores, sea stars, and sea urchins, were negatively correlated with degraded reefs health. The average size of commercial macro-invertebrates and the absolute fish biomass increased significantly with increasing values of the IRE. Higher total fish biomass was found on reefs with complex geomorphology compared to reefs with simple geomorphology (r(2) = 0.14, F = 44.05, P<0.0001) and the trophic biomass pyramid also changed, which supports the evidence of the inversion of biomass pyramids along the gradient of reefs' health. Our findings introduce a novel approach to classify the health of rocky reefs under different fishing regimes and therefore resultant community structures. Additionally, our IRH provides insight regarding the potential gains in total fish biomass that may result from the conservation and protection of reefs with more complex geomorphology. (C) 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license.

Leslie, HM, Basurto X, Nenadovic M, Sievanen L, Cavanaugh KC, Cota-Nieto JJ, Erisman BE, Finkbeiner E, Hinojosa-Arango G, Moreno-Baez M, Nagavarapu S, Reddy SMW, Sanchez-Rodriguez A, Siegel K, Ulibarria-Valenzuela JJ, Weaver AH, Aburto-Oropeza O.  2015.  Operationalizing the social-ecological systems framework to assess sustainability. Proceedings of the National Academy of Sciences of the United States of America. 112:5979-5984.   10.1073/pnas.1414640112   AbstractWebsite

Environmental governance is more effective when the scales of ecological processes are well matched with the human institutions charged with managing human-environment interactions. The social-ecological systems (SESs) framework provides guidance on how to assess the social and ecological dimensions that contribute to sustainable resource use and management, but rarely if ever has been operationalized for multiple localities in a spatially explicit, quantitative manner. Here, we use the case of small-scale fisheries in Baja California Sur, Mexico, to identify distinct SES regions and test key aspects of coupled SESs theory. Regions that exhibit greater potential for social-ecological sustainability in one dimension do not necessarily exhibit it in others, highlighting the importance of integrative, coupled system analyses when implementing spatial planning and other ecosystem-based strategies.

Erisman, B, Mascarenas-Osorio I, Lopez-Sagastegui C, Moreno-Baez M, Jimenez-Esquivel V, Aburto-Oropeza O.  2015.  A comparison of fishing activities between two coastal communities within a biosphere reserve in the Upper Gulf of California. Fisheries Research. 164:254-265.   10.1016/j.fishres.2014.12.011   AbstractWebsite

We engaged in collaborative research with two small-scale fishing communities inside the Upper Gulf of California Biosphere Reserve in Mexico, San Felipe (SF) and El Golfo de Santa Clara (GSC), to test how well the geographic heterogeneity of fishing activities within the reserve coincided with current regulations. We compared the two communities in terms of catch composition, fishing effort, ex-vessel prices and revenues, seasonal patterns in fishing activities in relation to the reproductive seasons of target species, and spatial patterns of fishing in relation to managed zones within the reserve. The top four species (Cynoscion othonopterus, Micropogonias megalops, Scomberomorus concolor, Litopenaeus stylirostris) in terms of relative effort, catch, and revenues were the same for both communities but overall fisheries production, effort, and revenues were higher in GSC than SF for these species. Fishing activities in GSC followed a predictable annual cycle that began with L stylirostris and were followed sequentially by the harvesting of C. othonopterus, M. megalops, and S. concolor during their respective spawning seasons, which were associated with seasonal variations in ex-vessel prices. Conversely, catch and revenues in SF were more diversified, less dependent on those four species, less seasonal, and did not show seasonal variations in prices. Interactions between fisheries and managed zones also differed such that SF interacted mainly with the southwest portion of the vaquita (Phocoena sinus) refuge, whereas GSC fished over a larger area and interacted mainly with the northeast portion of the vaquita refuge and the no-take zone. Our results indicate the two communities differ markedly in their socio-economic dependence on fisheries, their spatio-temporal patterns of fishing, their use of and impacts on species, coastal ecosystems and managed areas, and how different regulations may affect livelihoods. Regional management and conservation efforts should account for these differences to ensure the protection of endangered species and to sustain ecosystem services that maintain livelihoods and healthy coastal ecosystems. This study provides further evidence of the ability of collaborative research between scientists and fishers to produce robust and fine-scale fisheries and biological information that improves the collective knowledge and management of small-scale fisheries within marine protected areas. (C) 2014 Elsevier B.V. All rights reserved.

Girón-Nava, A, López-Sagástegui C, Aburto-Oropeza O.  2015.  On the conditions of the 2012 cannonball jellyfish (Stomolophus meleagris) bloom in Golfo de Santa Clara: a fishery opportunity? Fisheries Management and Ecology.   10.1111/fme.12115   Abstract

In 2012, a massive bloom of the cannonball jellyfish Stomolophus meleagris (Agassiz) occurred in El Golfo de Santa Clara (GSC), Sonora, Mexico, allowing the local artisanal fleet to land approximately 20 000 t, which generated almost 3.5 million US$ in revenue (Agencias 2013). Moreover, the bloom generated such enthusiasm that locals invested millions of dollars in infrastructure and equipment hoping that 2013 would bring another successful jellyfish fishing season. The jellyfish never arrived in 2013 and those investments became losses (Organización Editorial Mexicana 2013). This situation prompts the question whether it is possible and responsible to promote fisheries that are based on resources that become available as a result of bloom events. An analysis of environmental conditions that allowed such a massive bloom to occur was undertaken and a brief commentary on the long-term viability of such bloom-related fisheries is presented.

Ramirez-Valdez, A, Aburto-Oropeza O, Palacios-Salgado DS, Correa-Sandoval F, Ramirez-Valdez A, Villasenor-Derbez JC, Cota-Nieto JJ, Hinojosa-Arango G, Reyes-Bonilla H, Dominguez-Guerrero I, Hinojosa-Arango G, Villasenor-Derbez JC, Hernandez A.  2015.  The nearshore fishes of the Cedros Archipelago (north-eastern Pacific) and their biogeographic affinities. California Cooperative Oceanic Fisheries Investigations Reports. 56:143-167. AbstractWebsite

Located in the central region of the west coast of Baja California Peninsula, the Cedros Archipelago consists of five continental islands (Cedros Island, Natividad, San Benito Este, Medio, and Oeste), with Cedros being the largest island in the Mexican Pacific. This archipelago represents the biogeographic transition zone between the temperate and subtropical region and hence, the end of the geographic distribution of a large number of species. Based on field surveys, literature, and scientific collection records, an exhaustive species list of fishes associated with the archipelago and their biogeographic relationships is presented. The checklist includes 269 species belonging to 191 genera, 97 families, 31 orders, and 4 classes. Of the total species, 105 species were recorded in the field, 57 were the result of the literature review, and 218 species of the records were obtained from collections. A total of 14 biogeographic affinities are presented, where 51% of the species have warm-temperate or cold-temperate affinity and 37% have tropical-subtropical affinity. This work highlights the fish diversity present in a transition zone within the temperate and subtropical marine areas of the Northeastern Pacific. More importantly, it reveals a biogeographic region where a great number of species converge, and may be related with the evolutionary history of different taxa and the geological history of the region.

Gomez-Gutierrez, J, Funes-Rodriguez R, Arroyo-Ramirez K, Sanchez-Ortiz CA, Beltran-Castro JR, Hernandez-Trujillo S, Palomares-Garcia R, Aburto-Oropeza O, Ezcurra E.  2014.  Oceanographic mechanisms that possibly explain dominance of neritic-tropical zooplankton species assemblages around the Islas Marias Archipelago, Mexico. Latin American Journal of Aquatic Research. 42:1009-1034.   10.3856/vol42-issue5-fulltext-7   AbstractWebsite

The nearshore zooplankton species assemblage, identified per taxonomic groups (20) and per species for 12 selected groups, was analyzed from samples collected during November 2010 at four volcanic islands of the Islas Marias Archipelago (IMA), located 90-120 km offshore Nayarit, Mexico. From chlorophyll-a concentration and zooplankton biovolume perspective mesotrophic conditions prevailed in comparison with the Gulf of California during November. Crustaceans numerically dominated the zooplankton assemblage (92.3%) [Copepoda (79.2%), Decapoda larvae (4.7%), Cladocera (3.7%), Mysidacea (2.7%), and Euphausiacea (2.0%)]. The other 15 taxonomic groups (7.7% combined) accounted each one less than 1.5% of the relative abundance. Species richness of selected taxa (similar to 56%) included 259 taxa (121 identified to species, 117 to genus, and 21 not identified). Tropical species from neritic affinity clearly dominated zooplankton assemblage around IMA. Five tropical Copepoda species [Calanopia minor (Dana), Clausocalanus jobei Frost & Fleminger, Acrocalanus gibber Giesbrecht, Canthocalanus pauper (Giesbrecht), and Centropages furcatus (Dana)], a cladoceran Pseudevadne tergestina (Claus), and a Mysidacea species (Mysidium reckettsi Harrison & Bowman) dominated the zooplankton assemblage (accounting about 55% of total abundance of the identified species). Except C. furcatus, all these species are not abundant at oceanic regions of the central and northern Gulf of California. The similarity of multiple neritic and tropical species in the zooplankton assemblage from IMA and Cape Corrientes suggests strong coastal-insular plankton connectivity. Episodic current plumes associated with anomalous intense rivers discharge during rainy years, eddies generated by coastal upwelling event that move offshore, and northward regional oceanic circulation are the most likely mesoscale oceanographic processes that cause costal tropical zooplankton drift enhancing coastal-Archipelago species connectivity in this region.

Munguia-Vega, A, Jackson A, Marinone SG, Erisman B, Moreno-Baez M, Giron-Nava A, Pfister T, Aburto-Oropeza O, Torre J.  2014.  Asymmetric connectivity of spawning aggregations of a commercially important marine fish using a multidisciplinary approach. Peerj. 2   10.7717/peerj.511   AbstractWebsite

Understanding patterns of larval dispersal is key in determining whether no-take marine reserves are self-sustaining, what will be protected inside reserves and where the benefits of reserves will be observed. We followed a multidisciplinary approach that merged detailed descriptions of fishing zones and spawning time at 17 sites distributed in the Midriff Island region of the Gulf of California with a biophysical oceanographic model that simulated larval transport at Pelagic Larval Duration (PLD) 14, 21 and 28 days for the most common and targeted predatory reef fish, (leopard grouper Mycteroperca rosacea). We tested the hypothesis that source-sink larval metapopulation dynamics describing the direction and frequency of larval dispersal according to an oceanographic model can help to explain empirical genetic data. We described modeled metapopulation dynamics using graph theory and employed empirical sequence data from a subset of 11 sites at two mitochondrial genes to verify the model predictions based on patterns of genetic diversity within sites and genetic structure between sites. We employed a population graph describing a network of genetic relationships among sites and contrasted it against modeled networks. While our results failed to explain genetic diversity within sites, they confirmed that ocean models summarized via graph and adjacency distances over modeled networks can explain seemingly chaotic patterns of genetic structure between sites. Empirical and modeled networks showed significant similarities in the clustering coefficients of each site and adjacency matrices between sites. Most of the connectivity patterns observed towards downstream sites (Sonora coast) were strictly asymmetric, while those between upstream sites (Baja and the Midriffs) were symmetric. The best-supported gene flow model and analyses of modularity of the modeled networks confirmed a pulse of larvae from the Baja Peninsula, across the Midriff Island region and towards the Sonoran coastline that acts like a larval sink, in agreement with the cyclonic gyre (anti-clockwise) present at the peak of spawning (May-June). Our approach provided a mechanistic explanation of the location of fishing zones: most of the largest areas where fishing takes place seem to be sustained simultaneously by high levels of local retention, contribution of larvae from upstream sites and oceanographic patterns that concentrate larval density from all over the region. The general asymmetry in marine connectivity observed highlights that benefits from reserves are biased towards particular directions, that no-take areas need to be located upstream of targeted fishing zones, and that some fishing localities might not directly benefit from avoiding fishing within reserves located adjacent to their communities. We discuss the implications of marine connectivity for the current network of marine protected areas and no-take zones, and identify ways of improving it.

TinHan, T, Erisman B, Aburto-Oropeza O, Weaver A, Vazquez-Arce D, Lowe CG.  2014.  Residency and seasonal movements in Lutjanus argentiventris and Mycteroperca rosacea at Los Islotes Reserve, Gulf of California. Marine Ecology Progress Series. 501:191-206.   10.3354/meps10711   AbstractWebsite

A detailed understanding of inter- and intraspecific movement patterns is required to understand how marine species interact with surrounding ecological communities, their susceptibility to anthropogenic disturbance (e. g. fishing pressure), or the feasibility of management strategies. Between August 2010 and September 2012, we used acoustic telemetry to continuously monitor movements of 31 Lutjanus argentiventris (yellow snapper) and 25 Mycteroperca rosacea (leopard grouper) at Los Islotes, a small no-take reserve and reported spawning site for both species in the SW Gulf of California. Though the majority of fish from both species exhibited moderate levels of site fidelity to Los Islotes (snapper: present 49 +/- 30% of days since tagging, grouper: 64 +/- 30%), cluster analyses revealed multiple patterns of site fidelity within species. Approximately 30% of snapper exhibited decreases in site fidelity during the spawning season, and snapper did not spawn at the reserve during the study. Grouper spawning aggregations at Los Islotes were visually observed in 2011 and 2012, though the abundance of fish and the intensity of courtship behaviors were reduced in comparison with reported aggregations elsewhere in the Gulf. Three snapper and 2 grouper made repeated movements across pelagic waters between Los Islotes and Marisla Seamount, another documented aggregation site in the SW Gulf. The demonstrated variation in movements of these species over multiple temporal and spatial scales warrants consideration of movement patterns in assessments of reserve performance, as well as the combination of traditional fisheries regulations (e.g. size limits) with marine reserves throughout the Gulf.

Rubio-Cisneros, NT, Aburto-Oropeza O, Murray J, Gonzalez-Abraham CE, Jackson J, Ezcurra E.  2014.  Transnational ecosystem services: The potential of habitat conservation for waterfowl through recreational hunting activities. Human Dimensions of Wildlife. 19:1-16.: Routledge   10.1080/10871209.2013.819536   AbstractWebsite

This article explores transnational ecosystem services in North America, provided by winter habitat for waterfowl in western Mexico coastal lagoons, and the hunting industry supported by these birds in the United States. This article shows that the number of waterfowl harvested in the United States is related to the abundance of waterfowl wintering in Mexico. On average, this flow of ecosystem services annually yields US$ 4.68 million in hunting stamp sales in the western United States. A demand curve, fitted to duck hunting licenses as a function of stamp price and previous-year waterfowl harvest, estimated US$3?6 million in consumer surplus produced in addition to governmental stamp sales revenue. This strongly suggests that waterfowl wintering habitat in western Mexico is economically valuable to U.S. hunters. Because hunters may benefit substantially from these habitats they may be willing to pay for conservation efforts in western Mexico that can result in transnational benefits received in the United States.