Export 9 results:
Sort by: Author [ Title  (Asc)] Type Year
A B C D E F G H I J K L [M] N O P Q R S T U V W X Y Z   [Show ALL]
Vetter, EW, Dayton PK.  1998.  Macrofaunal communities within and adjacent to a detritus-rich submarine canyon system. Deep-Sea Research Part Ii-Topical Studies in Oceanography. 45:25-54.   10.1016/s0967-0645(97)00048-9   AbstractWebsite

Macrofaunal abundance, biomass, diversity and species assemblages within Scripps and La Jolla Submarine Canyons are compared with those on the nearby continental shelf and slope. Our primary objective was to examine the effect of detrital aggregates on infaunal communities within canyons, Two submarines, a remotely operated vehicle (ROV), and a Soutar box-corer were used to collect samples. Within the canyons, organic enrichment by macrophyte detritus was evident from canyon heads down to 550 m, and evidence of strong currents (coarse sediment) was found down to 700 m, Infaunal density and biomass were higher in the canyons than outside at all depths where comparative data were available (100-500m). Infaunal assemblages in canyons were distinct from those at reference stations. Both the canyon and non-canyons samples showed community differentiation with depth. Species diversity was generally high, but decreased with depth outside of canyons and increased with depth within the canyons. Low diversity at shallow depths within the canyon is attributed to a combination of organic enrichment and physical disturbance. Submarine canyons are commonly found to contain distinct species assemblages or higher faunal densities and/or biomass than nearby non-canyon regions at similar depths. Canyons are regular features along most ocean margins and appear to be important as sites of enhanced secondary production, provide diverse habitats, and act as conduits of coastal detritus to the deep-sea. (C) 1998 Elsevier Science Ltd. All rights reserved.

Davis, N, Vanblaricom GR, Dayton PK.  1982.  Man-made structures on marine sediments: effects on adjacent benthic communities. Marine Biology. 70:295-303.   10.1007/bf00396848   AbstractWebsite

This study (1975–1977) examines the effect of man-made structures on natural sand bottom communities in shallow water in San Diego County, southern California, USA. While there were shallow scour effects to 15 m around some artificial reefs, the reefs had no measurable effect on sand ripple patterns, grain size, organic carbon or infauna beyond the scoured areas. Foraging by reef-associated fishes produced profound alterations in the epifauna populations of the sea pen Stylatula elongata. The sea pen densities were 4 to 10 m-2 before the reefs were established, but within 5 mo were eliminated from distances greater than 200 m around the reefs. On the other hand, densities of the tube-building polychaetes Diopatra spp. seemed to be enhanced in the immediate vicinity of the artificial reef. Oil platforms and bridge pilings seem to have much more profound effects on the nearby sand communities than do the relatively small artificial reefs. In addition to the elimination of sea pens, Diopatra spp. densities increased from <1.0 m-2 in control areas to as many as 73 m-2 in the vicinity of oil platforms. Grain size and infauna were strongly affected by the oil platform.

Meffe, GK, Perrin WF, Dayton PK.  1999.  Marine mammal conservation: guiding principles and their implementation. Conservation and management of marine mammals. ( Twiss JR, Reeves RR, Montgomery S, Eds.).:437-454., Washington: Smithsonian Institution Press Abstract
Houde, E, Coleman F, Dayton P, Fluharty D, Kelleher G, Palumbi SR, Parma AM, Pimm SL, Roberts C, Smith SL, Somero G, Stoffle R, Wilen J.  2001.  Marine protected areas : tools for sustaining ocean ecosystems. ( on the and and in the States. N(US), Ed.).:xvi,272p.., Washington, D.C.: National Academy Press Abstract
Hyrenbach, KD, Forney KA, Dayton PK.  2000.  Marine protected areas and ocean basin management. Aquatic Conservation-Marine and Freshwater Ecosystems. 10:437-458.   10.1002/1099-0755(200011/12)10:6<437::aid-aqc425>;2-h   AbstractWebsite

1. All reserve designs must be guided by an understanding of natural history and habitat variability. 2. Differences in scale and predictability set aside highly dynamic pelagic systems from terrestrial and nearshore ecosystems, where wildlife reserves were first implemented. Yet, as in static systems, many pelagic species use predictable habitats to breed and forage. Marine protected areas (MPAs) could be designed to protect these foraging and breeding aggregations. 3. Understanding the physical mechanisms that influence the formation and persistence of these aggregations is essential in order to define and implement pelagic protected areas. We classify pelagic habitats according to their dynamics and predictability into three categories: static, persistent and ephemeral features. 4. While traditional designs are effective in static habitats, many important pelagic habitats are neither fixed nor predictable. Thus, pelagic protected areas will require dynamic boundaries and extensive buffers. 5. In addition, the protection of far-ranging pelagic vertebrates will require dynamic MPAs defined by the extent and location of large-scale oceanographic features. 6. Recent technological advances and our ability to implement large-scale conservation actions will facilitate the implementation of pelagic protected areas. 7. The establishment of pelagic MPAs should include enforcement, research and monitoring programmes to evaluate design effectiveness. 8. Ultimately, society will need a holistic management scheme for entire ocean basins. Such overarching management will rely on many innovative tools, including the judicious use of pelagic MPAs. Copyright (C) 2000 John Wiley & Sons, Ltd.

Parnell, PE, Dayton PK, Lennert-Cody CE, Rasmussen LL, Leichter JJ.  2006.  Marine reserve design: optimal size, habitats, species affinities, diversity, and ocean microclimate. Ecological Applications. 16:945-962.   10.1890/1051-0761(2006)016[0945:mrdosh];2   AbstractWebsite

The design of marine reserves is complex and fraught with uncertainty. However, protection of critical habitat is of paramount importance for reserve design. We present a case study as an example of a reserve design based on fine-scale habitats, the affinities of exploited species to these habitats, adult mobility, and the physical forcing affecting the dynamics of the habitats. These factors and their interaction are integrated in an algorithm that determines the optimal size and location of a marine reserve for a set of 20 exploited species within five different habitats inside a large kelp forest in southern California. The result is a reserve that encompasses similar to 42% of the kelp forest. Our approach differs fundamentally from many other marine reserve siting methods in which goals of area, diversity, or biomass are targeted a priori. Rather, our method was developed to determine how large a reserve must be within a specific area to protect a self-sustaining assemblage of exploited species. The algorithm is applicable across different ecosystems, spatial scales, and for any number of species. The result is a reserve in which habitat value is optimized for a predetermined set of exploited species against the area left open to exploitation. The importance of fine-scale habitat definitions for the exploited species off La Jolla is exemplified by the spatial pattern of habitats and the stability of these habitats within the kelp forest, both of which appear to be determined by ocean microclimate.

Fogarty, M, Bohnsack JA, Dayton PK.  2000.  Marine reserves and resource management. Seas at the millennium: An environmental evaluation: Volume III: Global Issues and Processes. ( Sheppard CRC, Ed.).:375-392.: Pergamon Abstract
Dayton, PK, Sala E, Tegner MJ, Thrush S.  2000.  Marine reserves: Parks, baselines, and fishery enhancement. Bulletin of Marine Science. 66:617-634. AbstractWebsite

Coastal zones are usually managed with two main objectives: (1) conservation/maintenance of biodiversity and. intrinsic ecosystem services and (2) maintenance of sustainable fisheries. The management needs that can be met with marine protected areas fall into corresponding categories. First, fully protected (that is, no-take) reserves-parks-offer benchmarks and protect ecosystem integrity while encouraging research, education, and aesthetic appreciation of nature. Second, by allowing focused local control of human impacts, marine protected areas can be used to focus more intense local management designed to increase yield and allow research to help define sustainability and protect against uncertainty by using carefully managed fisheries as a research tool. We have been gambling with the future by establishing a poor balance between short-term profit and long-term risks. The absence of meaningful, fully protected reserves has produced a situation in which there are virtually no areas north of the Antarctic in the world's oceans that have exploitable resources where scientists can study natural marine systems. In most areas the higher-order predators and many other important species have been virtually eliminated; many benthic habitats have been much changed by fishing activities. Without solid data documenting changes through time, the relative merits of various causes and effects that operate in complex ecological systems can always be argued. Without natural systems important questions cannot be studied-for example, how the ecosystem roles of various species can be assessed, how they can be managed in a sustainable manner, and how we can evaluate resilience or relative rates of recovery. Networks of fully-protected reserves could facilitate research into such questions, contribute to the recovery of many coastal systems, and enable society to enrich its existence by observing species that should be part of its heritage (Murray ct al., 1999). The use of marine protected areas as fishing refugia has met strong resistance by fishers and many managers, and it is misunderstood by many conservation biologists because different proponents have different, usually simplistic, visions. It is important to spell out the objectives of each proposed example. Our essential habitat perspective emphasizes that each situation depends on specific life-history parameters and emphasizes critical thresholds in population dynamics, including density and behavior for fertilization, transport processes, settlement, survivorship, and growth to maturity. These are extremely difficult problems, and we cannot expect simplistic solutions to be effective. The only basis for optimism is that most of the seriously affected species are not yet extinct, and we still have a little time to establish permanent fully protected reserves to allow mankind to appreciate its rich but much depleted biological heritage. At least in some systems recovery can be measured over short time scales (<10 yrs), whereas others are much slower. Society as a whole is the ultimate stakeholder, not only the commercial and sports fishing industries that so dominate the public arena. Society will have to play a more active role if these species and habitats are to be saved.

Thrush, SF, Cummings VJ, Dayton PK, Ford R, Grant J, Hewitt JE, Hines AH, Lawrie SM, Pridmore RD, Legendre P, McArdle BH, Schneider DC, Turner SJ, Whitlatch RB, Wilkinson MR.  1997.  Matching the outcome of small-scale density manipulation experiments with larger scale patterns an example of bivalve adult/juvenile interactions. Journal of Experimental Marine Biology and Ecology. 216:153-169.   10.1016/s0022-0981(97)00094-4   AbstractWebsite

Generalising or scaling up from small-scale experiments to lar er areas is an important challenge for both ecology and conservation biology. This study describes a technique that attempts to meet this challenge by combining spatial mapping with small-scale process experiments. Specifically, we evaluate the density effects of large individuals (> 15 mm shell length) of a tellinid bivalve (Macomona liliana Iredale) on macrofauna in 0.25 m(2) experimental plots within the natural density variation of large Macomona over a 12.5 ha site. By mapping the spatial distribution of large Macomona before conducting the experiment, we were able to identify homogeneous areas with different background densities of large Macomona and embed 22 experimental locations within the natural density-scape. Within each location, four experimental densities were added to plots from which all large macrofauna (>4 mm) had been previously removed. Macrofauna were sampled 22 days after the start of the experiment and significant negative treatment effects of high densities of large Macomona were identified by ANOVA for juvenile bivalves Macomona (<4 mm), Austrovenus stutchburyi (Gray) (<4 mm), the isopod Exosphaeroma falcatum Tattersall and the total number of individuals. Generalised linear models were then used to include the effect of background density variation of large Macomona in the analysis. Only Austrovenus (<4 mm) demonstrated a significant interaction between the background and experimental densities of large Macomona. This resulted from background densities of large Macomona having a significant effect on Austrovenus (<4 mm) in the two lowest density treatments only. Significant effects were detected only because we had planned the study to cover the various background densities of Macomona. The effect of experimental and background density variation of large Macomona on Macomona (<4 mm), Exospheroma, nemerteans and the total number of individuals were similar in direction and strength. Except for nemerteans, all relationships were negative, with low densities of macrofauna associated with high experimental and background densities of large Macomona. This implies that large-scale extrinsic factors (e.g., elevation, exposure to wave disturbance) are not the only features influencing the distribution of Macomona at the scale of the study site; intrinsic processes operating on smaller seals are also important. This scale-dependent response would not have been uncovered, had we not conducted a larger-scale survey in concert with the smaller-scale experiment. (C) 1997 Elsevier Science B.V.