14 research outputs found
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Quantifying fish production by threatened habitats
This is the final version of the article. It was first available from Wiley via http://dx.doi.org/10.1111/1365-2664.125761. Quantification of ecosystem services is increasingly valuable for conservation and restoration decision making. Structured habitats serve as nursery grounds by enhancing juvenile fish and mobile crustacean survival and abundance. This service is challenging to quantify due to ontogenetic shifts in habitat use by many species.
2. We reviewed available literature on the increased abundance of juvenile fish and mobile crustaceans in a key nursery habitat – Crassostrea virginica reefs in the USA. We modelled the growth and mortality of the enhanced species using three different natural mortality (M) estimates to provide estimates of the gross and net lifetime production and uncertainty that can be attributed to the habitat.
3. Recruitment of nineteen and twelve species were found to be enhanced by the addition of C. virginica reefs to previously unstructured habitat in the Gulf of Mexico and the South and Mid Atlantic USA, respectively. This increased recruitment is estimated to result in a mean lifetime enhancement in production of 397 ± 115 (1 SD) g m-2 y-1 in the Gulf of Mexico and 281 ± 56 g m-2 y-1 in the South and Mid Atlantic.
4. The two regions differed with regards to the identity of the enhanced species and their degree of augmentation. Thus, our results highlight the inadequacy of applying regional estimates of ecosystem services to global scales. Furthermore, estimates of total enhancement varied by up to a factor of 2.8 across the three methods of M estimation.
5. Our estimates are quantitative predictions of the ecological benefits derived from the restoration or conservation of a threatened habitat, and advance the field of restoration science beyond qualitative statements that just predict direction of benefit (e.g. increased or decreased). Quantification of the uncertainty in the production estimates further increases their utility for decision makers.
6. Synthesis and applications. Our results can be applied to the restoration or conservation of nursery habitats where habitat is limiting the recruitment of fish species. Quantitative estimates of fisheries productivity enhancement by habitats can be used by managers to determine the expected return on investment in restoration activities, provide testable predictions for monitoring programs, and communicate the value of restoring or conserving habitat.This work was supported by the National Fish and Wildlife Foundation (award no. 2009-0078-000) and by the National Partnership between The Nature Conservancy and NOAA’s Community-based Restoration Programme (award nos. NA07NMF4630136 and NA10NMF463008). Additional funding for the project was provided by the TNC-Shell Partnership and The Turner Foundation, Inc. and the National Science Foundation (OCE-1203859). The authors thank S. Bosarge for constructing the map of study locations and two knowledgeable reviewers for greatly improving this work
Oyster reef restoration fails to recoup global historic ecosystem losses despite substantial biodiversity gain
This is the final version. Available on open access from the American Association for the Advancement of Science via the DOI in this recordHuman activities have led to degradation of ecosystems globally. The lost ecosystem functions and services accumulate from the time of disturbance to the full recovery of the ecosystem and can be quantified as a "recovery debt," providing a valuable tool to develop better restoration practices that accelerate recovery and limit losses. Here, we quantified the recovery of faunal biodiversity and abundance toward a predisturbed state following structural restoration of oyster habitats globally. We found that while restoration initiates a rapid increase in biodiversity and abundance of reef-associated species within 2 years, recovery rate then decreases substantially, leaving a global shortfall in recovery of 35% below a predisturbed state. While efficient restoration methods boost recovery and minimize recovery shortfalls, the time to full recovery is yet to be quantified. Therefore, potential future coastal development should weigh up not only the instantaneous damage to ecosystem functions but also the potential for generational loss of services.Hong Kong Post-Doctoral FellowshipEnvironment and Conservation Fund Hong KongFaculty of Science (HKU) Rising Star Fun
Modelling and mapping regional-scale patterns of fishing impact and fish stocks to support coral-reef management in Micronesia
Aim: Use a fishery‐independent metric to model and map regional‐scale fishing impact, and demonstrate how this metric assists with modelling current and potential fish biomass to support coral‐reef management. We also examine the relative importance of anthropogenic and natural factors on fishes at biogeographical scales.
Location: Reefs of five jurisdictions in Micronesia.
Methods: A subset of 1,127 fish surveys (470 surveys) was used to calculate site‐specific mean parrotfish lengths (a proxy for cumulative fishing impact), which were modelled against 20 biophysical and anthropogenic variables. The resulting model was extrapolated to each 1 ha reef cell in the region to generate a fishing impact map. The remaining data (657 surveys) were then used to model fish biomass using 15 response variables, including fishing impact. This model was used to map estimated current regional fish standing stocks and, by setting fishing impact to 0, potential standing stocks.
Results: Human population pressure and distance to port were key anthropogenic variables predicting fishing impact. Total fish biomass was negatively correlated with fishing, but the influence of natural gradients of primary productivity, sea surface temperature, habitat quality and larval supply was regionally more important.
Main conclusions: Mean parrotfish length appears to be a useful fishery‐independent metric for modelling Pacific fishing impact, but considering environmental covariates is critical. Explicitly modelling fishing impact has multiple benefits, including generation of the first large‐scale map of tropical fishing impacts that can inform conservation planning. Using fishing impact data to map current and potential fish stocks provides further benefits, including highlighting the relative importance of fishing on fish biomass and identifying key biophysical variables that cause maximum potential biomass to vary significantly across the region. Regional‐scale maps of fishing, fish standing stocks and the potential benefits of protection are likely to lead to improved conservation outcomes during reserve network planning
Quantifying the historic contribution of Olympia oysters to filtration in Pacific Coast (USA) estuaries and the implications for restoration objectives
Ecological impacts of non-native Pacific oysters (Crassostrea gigas) and management measures for protected areas in Europe
Pacific oysters are now one of the most ‘globalised’ marine invertebrates. They dominate bivalve aquaculture production in many regions and wild populations are increasingly becoming established, with potential to displace native species and modify habitats and ecosystems. While some fishing communities may benefit from wild populations, there is now a tension between the continued production of Pacific oysters and risk to biodiversity, which is of particular concern within protected sites. The issue of the Pacific oyster therefore locates at the intersection between two policy areas: one concerning the conservation of protected habitats, the other relating to livelihoods and the socio-economics of coastal aquaculture and fishing communities. To help provide an informed basis for management decisions, we first summarise evidence for ecological impacts of wild Pacific oysters in representative coastal habitats. At local scales, it is clear that establishment of Pacific oysters can significantly alter diversity, community structure and ecosystem processes, with effects varying among habitats and locations and with the density of oysters. Less evidence is available to evaluate regional-scale impacts. A range of management measures have been applied to mitigate negative impacts of wild Pacific oysters and we develop recommendations which are consistent with the scientific evidence and believe compatible with multiple interests. We conclude that all stakeholders must engage in regional decision making to help minimise negative environmental impacts, and promote sustainable industry development
Oyster reef restoration fails to recoup global historic ecosystem losses despite substantial biodiversity gain
An End to Settlement on the Courthouse Steps - Mediated Settlement Conferences in North Carolina Superior Courts
Animal forests form the foundation of many important marine benthic habitats. However, a near ubiquitous lack of long-term scientific data raises significant challenges in assessing how these communities have changed over time in response to human impacts and how they might respond to future perturbations. To address these questions, alternative sources of data have to be gathered. Marine historical ecology is a rapidly growing field of research that uses historical sources to challenge our assumptions about what is natural in our marine environments. This discipline thus has the potential to fill some of the gaps in our understanding of animal forests through time. This chapter reviews how historical ecology research helps us to better understand the changes that have occurred in marine animal forests, focusing in particular upon oyster and shallow-water coral communities. The variety of data sources available and the methodologies that have been used to uncover past changes in these and related ecosystems are highlighted. The use of historical data to inform restoration efforts and emerging concepts in marine ecology, such as ecosystem service provision, is examined. Finally, the limitations of historical data and remaining knowledge gaps with regard to past animal forest communities are discussed
Forty questions of importance to the policy and practice of native oyster reef restoration in Europe
© 2020 The Authors. Aquatic Conservation: Marine and Freshwater Ecosystems published by John Wiley & Sons Ltd Oyster reefs are among the most threatened marine habitats globally. In Europe, oyster reefs have been extirpated from most locations within their historical range. Active restoration of the native oyster (Ostrea edulis) in Europe has grown substantially in recent years. In sharing experiences between oyster restoration projects in Europe at the Native Oyster Restoration Alliance conference, NORA2, in Edinburgh in May 2019, it became apparent that a number of similar barriers are experienced. This study identified the top 40 questions, which, if answered, would have the greatest influence on the policy and practice of oyster restoration in Europe. Initially 71 people were consulted across 28 institutions and 11 European countries to generate 194 questions. An established process of one round of pre-workshop voting followed by a one-day online workshop and two post-workshop rounds of voting resulted in the final 40 questions. Questions were broadly grouped into the following 10 themes: baselines, site selection, restoration methods, quantifying benefits, disease management, biosecurity, genetic diversity and population differentiation, policy and management, novel technologies, and current and future threats. We anticipate that this list will provide a starting point for developing collaborative projects across the NORA network, as well as assisting policy makers and funders with identifying key areas that need to be addressed in order to overcome existing barriers to scaling up oyster restoration in Europe.The NORA Secretariat are funded by the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU) and the German Federal Agency for Nature Conservation (Bundesamt für Naturschutz, BfN) through the Federal Program for Biodiversity and the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research within the project PROCEED (FKZ 3517685013). PzE is supported by The Nature Conservancy, Global Ocean Team. WJS is funded by Arcadia. JWPC is funded by NWO Domain Applied and Engineering Sciences under Grant 14494. WGS is funded by Glenmorangie and St Abbs Marine Station