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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.

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.

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.

Erisman, B, Heyman W, Kobara S, Ezer T, Pittman S, Aburto-Oropeza O, Nemeth RS.  2015.  Fish spawning aggregations: where well-placed management actions can yield big benefits for fisheries and conservation. Fish and Fisheries.   10.1111/faf.12132   Abstract

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.

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.

Hastings, PA, Craig MT, Erisman BE, Hyde JR, Walker HJ.  2014.  Fishes of Marine Protected Areas near La Jolla, California. Bulletin, Southern California Academy of Sciences. 113:200-231.: Southern California Academy of Sciences   10.3160/0038-3872-113.3.200   AbstractWebsite

The marine waters surrounding La Jolla, California have a diverse array of habitats and include several marine protected areas (MPAs). We compiled a list of the fish species occurring in the vicinity based on records of specimens archived in the Marine Vertebrate Collection (MVC) of the Scripps Institution of Oceanography (SIO). Collection of fishes from La Jolla in the MVC started in 1905, but greatly accelerated in 1944 when Carl L. Hubbs moved to SIO. By 1964, 90% of the 265 species recorded from the area had been collected and archived in the MVC. The fishes of La Jolla are dominated by species whose center of distribution is north of Point Conception (111 species), or between there and Punta Eugenia (96), with fewer species with southern distributions (57), and one exotic species. Reflecting the diversity of habitats in the area, soft-substrate species number 135, pelagic species 63, canyon-dwelling species 123 (including 35 rockfish species of the genus Sebastes),and hard-bottom species 140. We quantified the abundance of the latter group between 2002 and 2005 by counting visible fishes in transects along the rocky coastline of La Jolla, both within and adjacent to one of the region’s MPAs. In 500 transects, we counted over 90,000 fishes representing 51 species. The fish communities inside and outside of the MPA were similar and, typical of southern California kelp forests, numerically dominated by Blacksmith, Chromis punctipinnis (Pomacentridae), and Señorita, Oxyjulis californica (Labridae). Natural history collections such as the MVC are important resources for conservation biology for determining the faunal composition of MPAs and surrounding habitats, and documenting both the disappearance and invasion of species.

Miller, EF, Erisman B.  2014.  Long-term trends of Southern California's kelp and barred sand bass populations: A fishery-independent assessment. California Cooperative Oceanic Fisheries Investigations Reports. 55:119-127. AbstractWebsite

Power plant entrapment monitoring data provided insights on conditions leading up to and contributing to previously documented collapses of the southern California kelp bass (Paralabrax clathratus) and barred sand bass (P. nebulifer) fisheries. Individuals from all size classes from both species were taken over time at three sites spanning nearly 100 km along the southern California coast. Size class abundance peaked in the 200 to 250 mm SL size classes, or near the minimum size limit for the two southern California fisheries (250 mm SL). Annual modal lengths remained relatively static in P. clathratus, but significantly declined in P. nebulifer with a strong downsizing after 1993. Abundance indices for each species significantly declined over nearly four decades of monitoring: 97% in P. clathratus and 86% in P. nebulifer. Evidence suggests sporadic larval settlement by each species led to occasionally abundant year classes, such as 1982 (P. clathratus) and 1994 (P. nebulifer), interspersed with several consecutive years of comparably minimal settlement. No significant correlations with common climate indices including the Multivariate ENSO Index, Pacific Decadal Oscillation, and North Pacific Gyre Oscillation were detected for either species' year-class abundance index. The P. nebulifer year-class abundance index did significantly correlate, albeit weakly, with annual mean sea surface temperature. These results signify that, at this time, no environmental proxy for either species larval settlement exists.

Erisman, BE, Apel AM, MacCall AD, Romon MJ, Fujita R.  2014.  The influence of gear selectivity and spawning behavior on a data-poor assessment of a spawning aggregation fishery. Fisheries Research. 159:75-87.   10.1016/j.fishres.2014.05.013   AbstractWebsite

We applied several data-poor techniques to perform an assessment of the Gulf corvina (Cynoscion othonopterus) fishery in the Gulf of California from 1997 to 2012 and to investigate the effects of gear selectivity and age-dependent variation in spawning frequency on estimates of sustainability in spawning aggregation fisheries. The length composition of the catch varied significantly among years but showed no clear directional pattern. However, the average length was above the long term average after the implementation of a regulation that standardized mesh size of nets, and the average length of fish captured after the implementation was significantly higher than during previous periods. Results using three simple metrics based on catch length compositions indicated that fishing activities were sustainable due to the exclusion of juveniles from the fishery and the targeted harvest of adults at the optimal length. However, the low proportion of older, fecund fish in the fishery is a serious cause for concern. Modeled estimates of spawning potential ratios (SPR) were consistently higher when spawning frequency was assumed to be age invariant and were significantly higher after the implementation of gear regulations. However, SPR values only reached levels above 35%, a common reference point for sciaenid fishes, during the current fishing period (2010-2012) under conditions of age invariant spawning frequency. Results of this study support previous claims that suggest estimates of reproductive potential are highly sensitive to age-dependent variation in spawning frequency and imply that such details related to spawning behavior require more attention, particularly for fisheries that target spawning aggregations. Our results also suggest that spawning aggregations can be harvested sustainably through conventional regulations ifjuveniles are excluded, fish are harvested at optimal length, and older, fecund individuals are protected from harvest. Given the uncertainty of the status of the corvina fishery based on the discordant results of this study and the inherent vulnerability of the species to overfishing, We recommend the precautionary approach be applied to management decisions until more robust information is acquired on stock abundance, the relationship between spawning frequency and age or length, and reproductive output. (C) 2014 Elsevier B.V. All rights reserved.

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.

Rife, AN, Aburto-Oropeza O, Hastings PA, Erisman B, Ballantyne F, Wielgus J, Sala E, Gerber L.  2013.  Long-term effectiveness of a multi-use marine protected area on reef fish assemblages and fisheries landings. Journal of Environmental Management. 117:276-283.   10.1016/j.jenvman.2012.12.029   AbstractWebsite

The Loreto Bay National Park (LBNP) is a large, multi-use marine protected area in the Gulf of California, Mexico, where several types of small-scale commercial and recreational fishing are allowed, but where less than 1% of the park is totally protected from fishing. The LBNP was created in 1996; its management plan was completed in 2000, but it was not effectively implemented and enforced until 2003. Between 1998 and 2010, we monitored reef fish populations annually at several reefs inside and outside the LBNP to measure the effects of the park on fish assemblages. We also evaluated reported fisheries landings within the LBNP for the same time series. Our results show that reef fish biomass increased significantly after protection at a small no-take site at LBNP relative to the rest of the park. However, the multi-use part of LBNP where fishing is allowed (99% of its surface) has had no measurable effect on reef fish biomass relative to open access sites outside the park boundaries. Reported fisheries landings have decreased within the park while increasing in nearby unprotected areas. Although the current partial protection management regime has not allowed for reef fish populations to recover despite 15 years as a "protected area," we conclude that LBNP's regulations and management have maintained the conditions of the ecosystem that existed when the park was established. These results suggest that community livelihoods have been sustained, but a re-evaluation of the multi-use management strategy, particularly the creation of larger no-take zones and better enforcement, is needed to improve the reef fish populations in the park in order to ensure sustainable fisheries far into the future. These recommendations can be applied to all multi-use MPAs in Mexico where ecosystem recovery is not occurring despite maintenance of fish stocks. (C) 2013 Elsevier Ltd. All rights reserved.

Rife, AN, Erisman B, Sanchez A, Aburto-Oropeza O.  2013.  When good intentions are not enough ... Insights on networks of "paper park" marine protected areas. Conservation Letters. 6:200-212.   10.1111/j.1755-263X.2012.00303.x   AbstractWebsite

In efforts to protect the world's oceans, the Convention on Biological Diversity has moved the goal of establishing marine protected areas (MPAs) to cover 10% of the ocean from 2012 to 2020. This adjustment suggests that the rush to establish MPAs without proper resources does not resolve conservation problems. In fact, such actions may create a false sense of protection that camouflages degradation of marine ecosystems on regional scales. To exemplify this phenomenon, we reviewed MPA efficacy in the Gulf of California, Mexico, where some 23,300 km2 have been decreed as MPAs. With the exception of Cabo Pulmo National Park, MPAs have not met conservation or sustainability goals. We examined MPA budgets and foundations' investment in the region and found that funding for management is not the limiting factor in MPA efficacy, although funding for enforcement may be deficient. We conclude that MPAs have failed because of insufficient no-take zones, lack of enforcement, poor governance, and minimal community involvement. We need a new philosophy to implement MPAs to take advantage of the scientific knowledge and monetary investment that have been generated worldwide and ensure that they complement effective fisheries management outside their borders.

Erisman, BE, Petersen CW, Hastings PA, Warner RR.  2013.  Phylogenetic perspectives on the evolution of functional hermaphroditism in teleost fishes. Integrative and Comparative Biology. 53:736-754.   10.1093/icb/ict077   AbstractWebsite

Hermaphroditism is taxonomically widespread among teleost fishes and takes on many forms including simultaneous, protogynous, and protandrous hermaphroditism, bidirectional sex change, and androdioecy. The proximate mechanisms that influence the timing, incidence, and forms of hermaphroditism in fishes are supported by numerous theoretical and empirical studies on their mating systems and sexual patterns, but few have examined aspects of sex-allocation theory or the evolution of hermaphroditism for this group within a strict phylogenetic context. Fortunately, species-level phylogenetic reconstructions of the evolutionary history of many lineages of fishes have emerged, providing opportunities for understanding fine-scale evolutionary pathways and transformations of sex allocation. Examinations of several families of fishes with adequate data on phylogeny, patterns of sex allocation, mating systems, and with some form of hermaphroditism reveal that the evolution and expression of protogyny and other forms of sex allocation show little evidence of phylogenetic inertia within specific lineages but rather are associated with particular mating systems in accordance with prevalent theories about sex allocation. Transformations from protogyny to gonochorism in groupers (Epinephelidae), seabasses (Serranidae), and wrasses and parrotfishes (Labridae) are associated with equivalent transformations in the structure of mating groups from spawning of pairs to group spawning and related increases in sperm competition. Similarly, patterns of protandry, androdioecy, simultaneous hermaphroditism, and bidirectional sex change in other lineages (Aulopiformes, Gobiidae, and Pomacentridae) match well with particular mating systems in accordance with sex-allocation theory. Unlike other animals and plants, we did not find evidence that transitions between hermaphroditism and gonochorism required functional intermediates. Two instances in which our general conclusions might not hold include the expression of protandry in the Sparidae and the distribution of simultaneous hermaphroditism. In the Sparidae, the association of hypothesized mating systems and patterns of sex allocation were not always consistent with the size-advantage model (SAM), in that certain protandric sparids show evidence of intense sperm competition that should favor the expression of gonochorism. In the other case, simultaneous hermaphroditism does not occur in some groups of monogamous fishes, which are similar in ecology to the hermaphroditic serranines, suggesting that this form of sex allocation may be more limited by phylogenetic inertia. Overall, this work strongly supports sexual lability within teleost fishes and confirms evolutionary theories of sex allocation in this group of vertebrates.

Erisman, B, Aburto-Oropeza O, Gonzalez-Abraham C, Mascarenas-Osorio I, Moreno-Baez M, Hastings PA.  2012.  Spatio-temporal dynamics of a fish spawning aggregation and its fishery in the Gulf of California. Scientific Reports. 2   10.1038/srep00284   AbstractWebsite

We engaged in cooperative research with fishers and stakeholders to characterize the fine-scale, spatio-temporal characteristics of spawning behavior in an aggregating marine fish (Cynoscion othonopterus: Sciaenidae) and coincident activities of its commercial fishery in the Upper Gulf of California. Approximately 1.5-1.8 million fish are harvested annually from spawning aggregations of C. othonopterus during 21-25 days of fishing and within an area of 1,149 km(2) of a biosphere reserve. Spawning and fishing are synchronized on a semi-lunar cycle, with peaks in both occurring 5 to 2 days before the new and full moon, and fishing intensity and catch are highest at the spawning grounds within a no-take reserve. Results of this study demonstrate the benefits of combining GPS data loggers, fisheries data, biological surveys, and cooperative research with fishers to produce spatio-temporally explicit information relevant to the science and management of fish spawning aggregations and the spatial planning of marine reserves.

Erisman, BE, Hastings PA.  2011.  Evolutionary transitions in the sexual patterns of fishes: insights from a phylogenetic analysis of the seabasses (Teleostei: Serranidae). Copeia. :357-364.   10.1643/cg-10-086   AbstractWebsite

The evolution of hermaphroditism in fishes has intrigued scientists for over a century, but few have studied fine-scale evolutionary transitions between sexual patterns within the context of detailed hypotheses regarding phylogenetic relationships. Our phylogenetic reconstruction of sexual patterns in the seabasses (Teleostel: Serranidae) using a composite tree of 47 species is consistent with the hypothesis that protogyny is the ancestral condition in the family from which other sexual patterns evolved. Under this scenario, members of the Anthlinae retained protogynous hermaphroditism, as did the serranine genera Centropristis and Cheilidoperca. Gonochorism evolved once in the genus Paralabrax, and simultaneous hermaphroditism evolved once in the lineage that includes species of Hypoplectrus, Serranus, Serraniculus, and Diplectrum. Androdioecy evolved once within the genus Serranus and was derived from simultaneous hermaphroditism. Results from this study differ from previous hypotheses on the evolution of sexual patterns in seabasses and suggest that sexual patterns in fishes can evolve in several directions within single lineages and do not require functional intermediates.

Erisman, BE, Allen LG, Claisse JT, Pondella DJ, Miller EF, Murray JH.  2011.  The illusion of plenty: hyperstability masks collapses in two recreational fisheries that target fish spawning aggregations. Canadian Journal of Fisheries and Aquatic Sciences. 68:1705-1716.   10.1139/f2011-090   AbstractWebsite

Fisheries that target fish spawning aggregations can exhibit hyperstability, in which catch per unit effort (CPUE) remains elevated as stock abundance declines, but empirical support is limited. We compiled several fishery-dependent and fishery-independent data sets to assess stock trends in the barred sand bass (Paralabrax nebulifer) and the kelp bass (Paralabrax clathratus) in southern California, USA, evaluate the interaction between spawning aggregations and fishing activities, and test for hyperstability. Annual and seasonal trends from fisheries and population data indicate that regional stocks of both species have collapsed in response to overfishing of spawning aggregations and changes in environmental conditions. The aggregating behavior of fish and persistent targeting of spawning aggregations by recreational fisheries combined to produce a hyperstable relationship between CPUE and stock abundance in both species, which created the illusion that population levels were stable and masked fishery collapses. Differences in the rate of decline between the two species may be related to the size, duration, and spatial distribution of their spawning aggregations. Results of this study provide empirical evidence of hyperstability in aggregation-based fisheries and demonstrate that CPUE data be used with caution and given low weight when fishery-independent data are available.

Erisman, BE, Paredes GA, Plomozo-Lugo T, Cota-Nieto JJ, Hastings PA, Aburto-Oropeza O.  2011.  Spatial structure of commercial marine fisheries in Northwest Mexico. ICES Journal of Marine Science. 68:564-571.   10.1093/icesjms/fsq179   AbstractWebsite

The spatial structure of commercial marine fisheries in Northwest (NW) Mexico was investigated using official landings data from 39 local fisheries offices in the region. Multivariate analyses revealed a clear spatial pattern in fishing activities, in which there was a positive linear relationship between the species composition of fisheries offices and both latitude and longitude. Fisheries offices formed eight distinct clusters organized by similarities in geographic location, species-group composition, and coastal habitat type. Five of the eight clusters comprised offices from the same geographic region and coastal ecosystem, and the other three clusters contained the largest industrial fishing ports in NW Mexico. The results of this study suggest that NW Mexico would benefit from an ecosystem-based management framework that focuses on the direct, spatial connection that exists between coastal habitats, harvested species groups, and fishing activities within each region. Subdivision into five separate regions is proposed, with management attention paid specially to the few industrialized ports whose fishing capacities and geographic ranges of fishing far exceed the other areas.

Mascarenas-Osorio, I, Erisman B, Moxley J, Balart E, Aburto-Oropeza O.  2011.  Checklist of conspicuous reef fishes of the Bahia de los Angeles region, Baja California Norte, Mexico, with comments on abundance and ecological biogeography. Zootaxa. :60-68. AbstractWebsite

A first checklist of conspicuous reef fishes observed at 15 sites in the vicinity of Bahia de los Angeles from 2008 to 2010 is presented. A total of 70 species representing 31 families were observed. Species composition was similar to well studied regions in the southern Gulf of California, in that most species had distributions that span the Tropical Eastern Pacific but species endemic to Mexico or the Gulf of California ranked highest in relative abundance, frequency of occurrence, and mean density. Several species with temperate geographic distributions were more abundant and frequent than on reefs in the southern Gulf. Large-bodied, predatory species such as sharks and the Gulf Grouper, Mycteroperca jordani, were rare or absent.

Aburto-Oropeza, O, Erisman B, Galland GR, Mascarenas-Osorio I, Sala E, Ezcurra E.  2011.  Large recovery of fish biomass in a no-take marine reserve. Plos One. 6   10.1371/journal.pone.0023601   AbstractWebsite

No-take marine reserves are effective management tools used to restore fish biomass and community structure in areas depleted by overfishing. Cabo Pulmo National Park (CPNP) was created in 1995 and is the only well enforced no-take area in the Gulf of California, Mexico, mostly because of widespread support from the local community. In 1999, four years after the establishment of the reserve, there were no significant differences in fish biomass between CPNP (0.75 t ha(-1) on average) and other marine protected areas or open access areas in the Gulf of California. By 2009, total fish biomass at CPNP had increased to 4.24 t ha(-1) (absolute biomass increase of 3.49 t ha(-1), or 463%), and the biomass of top predators and carnivores increased by 11 and 4 times, respectively. However, fish biomass did not change significantly in other marine protected areas or open access areas over the same time period. The absolute increase in fish biomass at CPNP within a decade is the largest measured in a marine reserve worldwide, and it is likely due to a combination of social (strong community leadership, social cohesion, effective enforcement) and ecological factors. The recovery of fish biomass inside CPNP has resulted in significant economic benefits, indicating that community-managed marine reserves are a viable solution to unsustainable coastal development and fisheries collapse in the Gulf of California and elsewhere.

Erisman, BE, Galland GR, Mascarenas I, Moxley J, Walker HJ, Aburto-Oropeza O, Hastings PA, Ezcurra E.  2011.  List of coastal fishes of Islas Marias archipelago, Mexico, with comments on taxonomic composition, biogeography, and abundance. Zootaxa. :26-40. AbstractWebsite

The first comprehensive list of 318 coastal fish species recorded from the Islas Marias Archipelago, Mexico, was compiled from recent fieldwork, archival museum collections, and literature references. The jacks (Carangidae, 18 species) and the labrisomid blennies (Labrisomidae, 16) were the most speciose families. Most recorded species occur throughout the tropical eastern Pacific (160 species), while a significant proportion have wider ranges in the eastern Pacific (39), eastern Pacific and Indo-Pacific (39), eastern Pacific and Atlantic (3), or are circumtropical (39) in distribution. Three species occur in the Northeast Pacific, twenty-five are endemic to the Pacific coasts of Mexico, five are endemic to the Gulf of California, and three are endemic to Islas Marias. Cephalopholis panamensis (Epinephelidae), Epinephelus labriformis (Epinephelidae), Mulloidichthys dentatus (Mullidae), Stegastes flavilatus (Pomacentridae), Acanthurus xanthopterus (Acanthuridae), Pseudobalistes naufragium (Tetraodontidae), and Sufflamen verres (Tetraodontidae) were the dominant conspicuous species observed during underwater surveys in 2010. The absence or low abundance of commercially valuable shark, ray, and grouper species throughout the archipelago is discussed.

Erisman, B, Mascarenas I, Paredes G, de Mitcheson YS, Aburto-Oropeza O, Hastings P.  2010.  Seasonal, annual, and long-term trends in commercial fisheries for aggregating reef fishes in the Gulf of California, Mexico. Fisheries Research. 106:279-288.   10.1016/j.fishres.2010.08.007   AbstractWebsite

In order to assess the contribution of fish spawning aggregations and aggregating species to commercial marine fisheries in the Gulf of California we (1) investigated associations between the timing of spawning aggregations and monthly trends in commercial landings and ex-vessel revenues for aggregating reef fishes in the southwest Gulf of California and (2) compared present (2000-2005) and past (1956-1961) landings of aggregating species groups from the entire Gulf Species known to form seasonal spawning aggregations comprised the eight most important commercial reef fish fisheries of the southwest Gulf with respect to landings and ex-vessel revenues and three of these species increased in annual landings between 1999 and 2007 Peaks in mean monthly landings and revenues for five of eight aggregating species coincided with the timing of their spawning aggregations whereas commercial fisheries for the remaining three species did not specifically target spawning aggregation periods Comparisons of past and present landings showed an expansion of targeted species groups increased landings for most aggregating species groups and declines in the landings of several large-bodied species groups Our results suggest that targeted management of spawning aggregations is needed for some but not all species assessments on the interaction between fisheries and spawning aggregations are needed for most species and restrictions on certain gear types are necessary to create sustainable fisheries for aggregating fishes in the Gulf (C) 2010 Elsevier B V All rights reserved

Erisman, BE, Craig MT, Hastings PA.  2010.  Reproductive biology of the Panama graysby Cephalopholis panamensis (Teleostei: Epinephelidae). Journal of Fish Biology. 76:1312-1328.   10.1111/j.1095-8649.2010.02567.x   AbstractWebsite

The reproductive biology of the Panama graysby Cephalopholis panamensis was studied from collections and behavioural observations made in the Gulf of California from 2001 to 2006. Histological examinations, particularly the identification of gonads undergoing sexual transition, confirmed a protogynous hermaphroditic sexual pattern. The population structure and mating behaviour provided further support for protogyny. Size and age distributions by sex were bimodal, with males larger and older than females and sex ratios biased towards females. Mating groups consisted of a large male and several smaller females, and courtship occurred in pairs during the evening. Results on spawning periodicity and seasonality were incomplete, but histological data, monthly gonado-somatic indices (I(G)) and behavioural observations suggest that adults spawned around the full moon from May to September. Certain aspects of their reproductive biology (e.g. protogyny and low egg production) indicate that C. panamensis is particularly vulnerable to fishing and would benefit from a management policy in Mexico.