Marine reserve effects on fishery profits : a comment on White et al. (2008)

This paper is not subject to U.S. copyright. The definitive version was published in Ecology Letters 12 (2009): E9-E11, doi:10.1111/j.1461-0248.2008.01272.x.A recent study (White et al. 2008) claimed that fishery profits will often be higher with management that employs no-take marine reserves than conventional fisheries management alone. However, this conclusion was based on the erroneous assumption that all landed fish have equal value regardless of size, and questionable assumptions regarding density-dependence. Examination of an age-structured version of the White et al. (2008) model demonstrates that their results are not robust to these assumptions. Models with more realistic assumptions generally do not indicate increased fishery yield or profits from marine reserves except for overfished stocks

William (Bill) Peterson's contributions to ocean science, management, and policy

© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Schwing, F. B., Sissenwine, M. J., Batchelder, H., Dam, H. G., Gomez-Gutierrez, J., Keister, J. E., Liu, H., & Peterson, J. O. William (Bill) Peterson's contributions to ocean science, management, and policy. Progress in Oceanography, 182, (2020): 102241, doi:10.1016/j.pocean.2019.102241.In addition to being an esteemed marine ecologist and oceanographer, William T. (Bill) Peterson was a dedicated public servant, a leader in the ocean science community, and a mentor to a generation of scientists. Bill recognized the importance of applied science and the need for integrated “big science” programs to advance our understanding of ecosystems and to guide their management. As the first US GLOBEC program manager, he was pivotal in transitioning the concept of understanding how climate change impacts marine ecosystems to an operational national research program. The scientific insight and knowledge generated by US GLOBEC informed and advanced the ecosystem-based management approaches now being implemented for fishery management in the US. Bill held significant leadership roles in numerous international efforts to understand global and regional ecological processes, and organized and chaired a number of influential scientific conferences and their proceedings. He was passionate about working with and training young researchers. Bill’s academic affiliations, notably at Stony Brook and Oregon State Universities, enabled him to advise, train, and mentor a host of students, post-doctoral researchers, and laboratory technicians. Under his collegial guidance they became critical independent thinkers and diligent investigators. His former students and colleagues carry on Bill Peterson’s legacy of research that helps us understand marine ecosystems and informs more effective resource stewardship and conservation

Aquaculture and capture fisheries : a conceptual approach toward an integrated economic-ecological analysis

Author Posting. © The Author(s), 2012. This is the author's version of the work. It is posted here by permission of Taylor & Francis for personal use, not for redistribution. The definitive version was published in Aquaculture Economics & Management 16 (2012): 167-181, doi:10.1080/13657305.2012.678551.This study presents a framework for analyzing the interactions between aquaculture and capture fisheries in the context of ecosystem-based management. We extend a model of the economic and ecological systems in coastal New England by incorporating an aquaculture sector in a computable general equilibrium (CGE) model and by examining the forage fish and aquaculture link in a marine food web. We show that aquaculture and commercial fisheries interact in a complex way throughout the economic and ecological systems.This work was supported by the NOAA Saltonstall-Kennedy Grant Program (Award No. NA09NMF4270097), the MIT Sea Grant College Program (NOAA Award No. NA10OAR4170086, Subaward No. 5710002974), and the Johnson Endowment of the WHOI Marine Policy Center.2013-06-0

Why compare marine ecosystems?

This paper is not subject to U.S. copyright. The definitive version was published in ICES Journal of Marine Science: Journal du Conseil 67 (2010): 1-9, doi:10.1093/icesjms/fsp221.Effective marine ecosystem-based management (EBM) requires understanding the key processes and relationships controlling the aspects of biodiversity, productivity, and resilience to perturbations. Unfortunately, the scales, complexity, and non-linear dynamics that characterize marine ecosystems often confound managing for these properties. Nevertheless, scientifically derived decision-support tools (DSTs) are needed to account for impacts resulting from a variety of simultaneous human activities. Three possible methodologies for revealing mechanisms necessary to develop DSTs for EBM are: (i) controlled experimentation, (ii) iterative programmes of observation and modelling ("learning by doing"), and (iii) comparative ecosystem analysis. We have seen that controlled experiments are limited in capturing the complexity necessary to develop models of marine ecosystem dynamics with sufficient realism at appropriate scales. Iterative programmes of observation, model building, and assessment are useful for specific ecosystem issues but rarely lead to generally transferable products. Comparative ecosystem analyses may be the most effective, building on the first two by inferring ecosystem processes based on comparisons and contrasts of ecosystem response to human-induced factors. We propose a hierarchical system of ecosystem comparisons to include within-ecosystem comparisons (utilizing temporal and spatial changes in relation to human activities), within-ecosystem-type comparisons (e.g. coral reefs, temperate continental shelves, upwelling areas), and cross-ecosystem-type comparisons (e.g. coral reefs vs. boreal, terrestrial vs. marine ecosystems). Such a hierarchical comparative approach should lead to better understanding of the processes controlling biodiversity, productivity, and the resilience of marine ecosystems. In turn, better understanding of these processes will lead to the development of increasingly general laws, hypotheses, functional forms, governing equations, and broad interpretations of ecosystem responses to human activities, ultimately improving DSTs in support of EBM

Frequency responses of age-structured populations: Pacific salmon as an example

Increasing evidence of the effects of changing climate on physical ocean conditions and long-term changes in fish populations adds to the need to understand the effects of stochastic forcing on marine populations. Cohort resonance is of particular interest because it involves selective sensitivity to specific time scales of environmental variability, including that of mean age of reproduction, and, more importantly, very low frequencies (i.e., trends). We present an age-structured model for two Pacific salmon species with environmental variability in survival rate and in individual growth rate, hence spawning age distribution. We use computed frequency response curves and analysis of the linearized dynamics to obtain two main results. First, the frequency response of the population is affected by the life history stage at which variability affects the population; varying growth rate tends to excite periodic resonance in age structure, while varying survival tends to excite low-frequency fluctuation with more effect on total population size. Second, decreasing adult survival strengthens the cohort resonance effect at all frequencies, a finding that addresses the question of how fishing and climate change will interact.Comment: much revised: the version accepted by Theoretical Population Biolog

The consumption of zooplankton by early life stages of fish in the North Sea

Previous work has shown that during the 1970s, fish and carnivorous macrozooplankton together consumed ~22 gC m-2 year-1 of mesozooplankton, principally copepods. Consumption declined to ~17 gC m-2 year-1 during the 1990s, mainly because of a reduction in fish production. The zooplankton production required to meet this demand seems to be approximately accounted for by estimates of new primary production, but there are additional sinks for zooplankton production attributable to predation by, for example, gelatinous species. Additionally, the consumption of zooplankton by early life stages of fish is difficult to assess and could be larger than implied by the earlier analysis. Here, the role of fish early life stages in zooplankton consumption is reassessed, and found to be approximately double that previously estimated. Some 28% of the zooplankton consumption by fish is now estimated to be attributable to early life stages, resulting in an estimate of zooplankton consumption by the fish community as a whole 14% higher. Taken overall, the consumption of zooplankton production by fish and other planktivorous predators is now estimated to be 19-25 gC m-2 year-1

Yield Analysis for the Long-finned Squid, Loli•o pealei (LeSueur)

A modified version of yield-per-recruit analysis wasused to estimate potential yields in the Loligo pealei fishery off the northe stern USA. The mode1 accepts monthly values of growth and fishing, spawning and natural mortality rates and assumes two cohorts per year class, as associated with pawning peaks. Two patterns of exploitation were examined by simulatting dominance of the international fishery (offshore, winter fishing coupled with the domestic inshore summer fishing) and the domestic fishery alone through varistion of the monthly pattern of fishing mortalita. Parameter estimates were derived from survey catch per tow and commercial catch data

Comparing species and ecosystem-based estimates of fisheries yields

Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Fisheries Research 111 (2011): 139-144, doi:10.1016/j.fishres.2011.07.009.Three methods are described to estimate potential yields of commercial fish species: (i) single-species calculation of maximum sustainable yields, and two ecosystem-based methods derived from published results for (ii) energy flow and for (iii) community structure. The requirements imposed by food-web fluxes, and by patterns of relative abundance, provide constraints on individual species. These constraints are used to set limits to ecosystem-based yields (EBY); these limits, in turn, provide a comparison with the usual estimates of maximum sustainable yields (MSY). We use data on cod and haddock production from Georges Bank for the decade 1993-2002 to demonstrate these methods. We show that comparisons among the three approaches can be used to demonstrate that ecosystem based estimates of yields complement, rather than supersede, the single-species estimates. The former specify the significant changes required in the rest of the ecosystem to achieve a return to maximum sustainable levels for severely depleted commercial fish stocks. The overall conclusion is that MSY defines changes required in particular stocks, whereas EBY determines the changes required in the rest of the ecosystem to realize these yields. Species specific MSY only has meaning in the context of the prey, predators and competitors that surround it.We acknowledge NSF awards OCE081459 (to DJG) and OCE0814474 (to JHS)

Predicting global habitat suitability for stony corals on seamounts

Aim Globally, species distribution patterns in the deep sea are poorly resolved, with spatial coverage being sparse for most taxa and true absence data missing. Increasing human impacts on deep-sea ecosystems mean that reaching a better understanding of such patterns is becoming more urgent. Cold-water stony corals (Order Scleractinia) form structurally complex habitats (dense thickets or reefs) that can support a diversity of other associated fauna. Despite their widely accepted ecological importance, records of scleractinian corals on seamounts are patchy and simply not available for most of the global ocean. The objective of this paper is to model the global distribution of suitable habitat for stony corals on seamounts. Location Seamounts worldwide. Methods We compiled a database containing all accessible records of scleractinian corals on seamounts. Two modelling approaches developed for presence-only data were used to predict global habitat suitability for seamount scleractinians: maximum entropy modelling (Maxent) and environmental niche factor analysis (ENFA). We generated habitat-suitability maps and used a cross-validation process with a threshold-independent metric to evaluate the performance of the models. Results Both models performed well in cross-validation, although the Maxent method consistently outperformed ENFA. Highly suitable habitat for seamount stony corals was predicted to occur at most modelled depths in the North Atlantic, and in a circumglobal strip in the Southern Hemisphere between 20° and 50° S and shallower than around 1500 m. Seamount summits in most other regions appeared much less likely to provide suitable habitat, except for small near-surface patches. The patterns of habitat suitability largely reflect current biogeographical knowledge. Environmental variables positively associated with high predicted habitat suitability included the aragonite saturation state, and oxygen saturation and concentration. By contrast, low levels of dissolved inorganic carbon, nitrate, phosphate and silicate were associated with high predicted suitability. High correlation among variables made assessing individual drivers difficult. Main conclusions Our models predict environmental conditions likely to play a role in determining large-scale scleractinian coral distributions on seamounts, and provide a baseline scenario on a global scale. These results present a first-order hypothesis that can be tested by further sampling. Given the high vulnerability of cold-water corals to human impacts, such predictions are crucial tools in developing worldwide conservation and management strategies for seamount ecosystems. © 2009 Blackwell Publishing Ltd