Broad-scale surveys for the economically valuable gastropod queen conch in historically important fishing grounds of the Bahamian archipelago provide opportunity to explore the impact of variable fishing intensity on population structures. Visual surveys spanning two decades showed that densities of mature individuals had a significant negative relationship with an index of fishing pressure (FP). Average shell length in a population was not related to FP, but shell lip thickness (an index of conch age) declined significantly with FP. Repeated surveys in three fishing grounds revealed that densities of mature conch have declined in all of those locations and the populations have become younger with time. Densities have also declined significantly in three repeated surveys (over 22 years) conducted in a large no-take fishery reserve. Unlike fished populations, the protected population has aged and appears to be declining for lack of recruitment. In all fishing grounds except those most lightly fished, densities of adult conch are now below that needed for successful mating and reproduction. It is clear that queen conch populations in The Bahamas have undergone serial depletion, nearing fishery collapse, and a wide range of recommendations aimed at stock recovery are offered including a broader network of no-take reserves.
The following titles are freely-available, or include a link to a preprint or postprint.
This study describes the pathologic findings and most probable causes of death (CD) of 224 cetaceans stranded along the coastline of the Canary Islands (Spain) over a 7-year period, 2006–2012. Most probable CD, grouped as pathologic categories (PCs), was identified in 208/224 (92.8%) examined animals. Within natural PCs, those associated with good nutritional status represented 70/208 (33.6%), whereas, those associated with significant loss of nutritional status represented 49/208 (23.5%). Fatal intra- and interspecific traumatic interactions were 37/208 (17.8%). Vessel collisions included 24/208 (11.5%). Neonatal/perinatal pathology involved 13/208 (6.2%). Fatal interaction with fishing activities comprised 10/208 (4.8%). Within anthropogenic PCs, foreign body-associated pathology represented 5/208 (2.4%). A CD could not be determined in 16/208 (7.7%) cases. Natural PCs were dominated by infectious and parasitic disease processes. Herein, our results suggest that between 2006 and 2012, in the Canary Islands, direct human activity appeared responsible for 19% of cetaceans deaths, while natural pathologies accounted for 81%. These results, integrating novel findings and published reports, aid in delineating baseline knowledge on cetacean pathology and may be of value to rehabilitators, caregivers, diagnosticians and future conservation policies.
Tropical estuaries are one of the most valuable ecosystems on the planet because of the number of ecosystem services they provide. The increasing anthropogenic pressure to which these estuaries are subject has caused a reduction in their natural capital stock. Therefore, the application of a pragmatic and rational ecosystem-based management approach to sustainably manage the multiple ecosystem services provided by this ecosystem is necessary. The aim of our study is to present an approach that combines prospective scenarios with habitat-based perspective to assess the supply capacity of ecosystem services, plus determine the impact of protected areas in an urbanized tropical estuary. The current situation and two scenarios were generated to evaluate the capacity of habitats to supply ecosystem services. This type of assessment will allow the decision makers to visualize the effect of their choices or the occurrence of events which might produce significant changes in the estuary. Thus, over time, measures can be taken to sustain the supply of ecosystem services. We determined that the establishment of protected areas have a positive impact; however, the effect is not the same for all of them. Consequently, indicating that actions such as community participation, research, education, management planning and infrastructure development must accompany the development of a protected area.
We have observed that marine macroalgae produce sound during photosynthesis. The resultant soundscapes correlate with benthic macroalgal cover across shallow Hawaiian coral reefs during the day, despite the presence of other biological noise. Likely ubiquitous but previously overlooked, this source of ambient biological noise in the coastal ocean is driven by local supersaturation of oxygen near the surface of macroalgal filaments, and the resultant formation and release of oxygen-containing bubbles into the water column. During release, relaxation of the bubble to a spherical shape creates a monopole sound source that ‘rings’ at the Minnaert frequency. Many such bubbles create a large, distributed sound source over the sea floor. Reef soundscapes contain vast quantities of biological information, making passive acoustic ecosystem evaluation a tantalizing prospect if the sources are known. Our observations introduce the possibility of a general, volumetrically integrative, noninvasive, rapid and remote technique for evaluating algal abundance and rates of primary productivity in littoral aquatic communities. Increased algal cover is one of the strongest indicators for coral reef ecosystem stress. Visually determining variations in algal abundance is a time-consuming and expensive process. This technique could therefore provide a valuable tool for ecosystem management but also for industrial monitoring of primary production, such as in algae-based biofuel synthesis.
Based on a validated underwater oil spill model and the hydrodynamic background provided by an unstructured grid, finite-volume, coastal ocean model (FVCOM), a series of numerical experiments are conducted to study the impact of error in ocean dynamical background currents on the 3D transport of underwater spilled oil, in terms of three metrics including oil centroid position, sweeping area, and sweeping volume. Numerical result shows that a larger error in ocean dynamical background currents results in a larger model error expectation and uncertainty for all three metrics. As model time increases, the model error mainly increases and the error growth rate varies unevenly. The sensitivity of the oil spill model to background current error can be interpreted as an integrated result of the temporal and spatial variations of the background current and the movement of oil droplets of different sizes.
There has been a recent shift in global perception of plastics in the environment, resulting in a call for greater action. Science and the popular media have highlighted plastic as an increasing stressor. Efforts have been made to confer protected status to some remote locations, forming some of the world’s largest Marine Protected Areas, including several UK overseas territories. We assessed plastic at these remote Atlantic Marine Protected Areas, surveying the shore, sea surface, water column and seabed, and found drastic changes from 2013–2018. Working from the RRS James Clark Ross at Ascension, St. Helena, Tristan da Cunha, Gough and the Falkland Islands (Figure 1A), we showed that marine debris on beaches has increased more than 10 fold in the past decade. Sea surface plastics have also increased, with in-water plastics occurring at densities of 0.1 items m–3; plastics on seabeds were observed at ≤ 0.01 items m–2. For the first time, beach densities of plastics at remote South Atlantic sites approached those at industrialised North Atlantic sites. This increase even occurs hundreds of meters down on seamounts. We also investigated plastic incidence in 2,243 animals (comprising 26 species) across remote South Atlantic oceanic food webs, ranging from plankton to seabirds. We found that plastics had been ingested by primary consumers (zooplankton) to top predators (seabirds) at high rates. These findings suggest that MPA status will not mitigate the threat of plastic proliferation to this rich, unique and threatened biodiversity.
Benthic–pelagic coupling refers to the ecological relationships between benthic and pelagic environments. Studying such links is particularly useful to understand biological variation in intertidal organisms along marine coasts. Filter-feeding invertebrates are important on marine rocky shores, so they have often been used to investigate benthic–pelagic coupling. Most studies, however, were done on eastern ocean boundary coasts highly influenced by upwelling. To evaluate the extent of benthic–pelagic coupling on a western ocean boundary coast, we conducted a 5-year study spanning 415 km of the Atlantic coast of Nova Scotia (Canada). Between 2014 and 2018, we annually measured intertidal barnacle growth in experimental clearings created on the rocky substrate at eight wave-exposed locations. We then examined the relationships with chlorophyll-a concentration (Chl-a), a commonly used proxy for the abundance of phytoplankton (food for barnacle nauplius larvae and benthic stages). For every year and location, we used satellite data to calculate Chl-a averages for a period ranging from the early spring (when likely most larvae were in the water) to the summer (when barnacle size was measured after weeks of growth following spring benthic recruitment). The relationships were always positive, Chl-a explaining nearly half, or more, of the variation in barnacle size in four of the five studied years. These are remarkable results because they were based on a relatively limited number of locations (which often curtails statistical power) and point to the relevance of pelagic food supply to explain variation in barnacle growth along this western ocean boundary coast.
Climate change research aims to understand global environmental change and how it will impact nature and society. The broad scope of climate change impacts means that successful adaptation and mitigation efforts will require an unprecedented collaboration effort that unites diverse disciplines and is able to rapidly respond to evolving climate issues (IPCC, 2014). However, to achieve this aim, climate change research practices need updating: key research findings remain behind journal paywalls, and scientific progress can be impeded by low levels of reproducibility and transparency (Ellison, 2010; Morueta-Holme et al., 2018), individual data ownership (Hampton et al., 2015), and inefficient research workflows (Lowndes et al., 2017). Furthermore, the level of public interest and policy engagement on climate change issues relies on fast communication of academic research to public institutions, with the result that the societal impact of climate change studies will differ according to their public availability and exposure. Here, we argue that by adopting open science (OS) principles, scientists can advance climate change research and accelerate efforts to mitigate impacts; especially for highly vulnerable developing regions of the world where research capacity is limited. We underscore the specific benefits of OS in raising the academic and societal impact of climate change research using citation and media metrics.
Recent decades have seen an increasing emphasis on (re)structuring marine governance regulation to fit relevant natural systems in terms of scale and spatial scope, and thus also on the delimitation of spatial units. Being at the heart of ecosystem based management, this focus on the relationship between scale and space in nature and in regulatory systems necessitates an increased awareness of the use of spatial and scale-related concepts in marine governance regulation. Using the regulatory context of the Baltic Sea as the focal point, this article examines concepts central to marine governance such as ‘ecosystem’, ‘water body’ and ‘marine waters’. It investigates how changes in the physical environment are reflected in the legal concepts, but also how these concepts affect the understanding or definition of the ‘natural’ phenomena ostensibly representing the scales on which the regulatory system should be premised.
Inland aquatic ecosystems play an important part in the delivery and support of ecosystem services. However, these ecosystems are subject to stressors associated with human activities such as invasive species introduction and landscape alteration. There is a delicate balance between maintaining good status of the ecosystem whilst meeting the needs of those stakeholders dependent on the ecosystem services it supplies, and where there are many different stakeholders, each with different aspirations and dependencies on the ecosystem, it can be difficult to strike a balance on suitable management measures to put in place. A better understanding of the interactions between the human and ecological functions of the ecosystem (a socio-ecological systems (SES) approach) can enable an effective dialogue to be opened to secure management solutions of best fit. In this study we took a SES approach to explore the dependencies and interactions in the Lough Erne catchment with a range of stakeholders representing the use of the Lough. In particular, we explored how individual stakeholder goals were perceived to be affected by both the biodiversity and activities found in the catchment. Results suggest there are distinct components deemed integral to the success of stakeholder goals in this system, including ‘key habitat components’ and ‘policy relevant species’, as well as activities associated with ‘conservation and recreation’ and ‘scientific research’. Those components which were seen to limit the potential achievement of most goals included invasive species, and in particular, more recently introduced invasives, as well as extractive industries. Consideration of the similarity in goals based on their perceived interactions with the activities and biodiversity of the system indicated that there were shared dependencies between some stakeholders, but also differences that highlight the potential for conflict. Future management scenarios should take consideration of the key limiting and enabling factors identified here.
Bottom trawlers land around 19 million tons of fish and invertebrates annually, almost one-quarter of wild marine landings. The extent of bottom trawling footprint (seabed area trawled at least once in a specified region and time period) is often contested but poorly described. We quantify footprints using high-resolution satellite vessel monitoring system (VMS) and logbook data on 24 continental shelves and slopes to 1,000-m depth over at least 2 years. Trawling footprint varied markedly among regions: from <10% of seabed area in Australian and New Zealand waters, the Aleutian Islands, East Bering Sea, South Chile, and Gulf of Alaska to >50% in some European seas. Overall, 14% of the 7.8 million-km2 study area was trawled, and 86% was not trawled. Trawling activity was aggregated; the most intensively trawled areas accounting for 90% of activity comprised 77% of footprint on average. Regional swept area ratio (SAR; ratio of total swept area trawled annually to total area of region, a metric of trawling intensity) and footprint area were related, providing an approach to estimate regional trawling footprints when high-resolution spatial data are unavailable. If SAR was ≤0.1, as in 8 of 24 regions, there was >95% probability that >90% of seabed was not trawled. If SAR was 7.9, equal to the highest SAR recorded, there was >95% probability that >70% of seabed was trawled. Footprints were smaller and SAR was ≤0.25 in regions where fishing rates consistently met international sustainability benchmarks for fish stocks, implying collateral environmental benefits from sustainable fishing.
This paper analyzes the trophic role of Pacific herring, the potential consequences of its depletion, and the impacts of alternative herring fishing strategies on a Northeast Pacific food web in relation to precautionary, ecosystem-based management. We used an Ecopath with Ecosim ecosystem model parameterized for northern British Columbia (Canada), employing Ecosim to simulate ecosystem effects of herring stock collapse. The ecological impacts of various herring fishing strategies were investigated with a Management Strategy Evaluation algorithm within Ecosim, accounting for variability in climatic drivers and stock assessment errors. Ecosim results suggest that herring stock collapse would have cascading impacts on much of the pelagic food web. Management Strategy Evaluation results indicate that herring and their predators suffer moderate impacts from the existing British Columbia harvest control rule, although more precautionary management strategies could substantially reduce these impacts. The non-capture spawn-on-kelp fishery, traditionally practiced by many British Columbia and Alaska indigenous peoples, apparently has extremely limited ecological impacts. Our simulations also suggest that adopting a maximum sustainable yield management strategy in Northeast Pacific herring fisheries could generate strong, cascading food web effects. Furthermore, climate shifts, especially when combined with herring stock assessment errors, could strongly reduce the biomasses and resilience of herring and its predators. By clarifying the trophic role of Pacific herring, this study aims to facilitate precautionary fisheries management via evaluation of alternative fishing strategies, and thereby to inform policy tradeoffs among multiple ecological and socioeconomic factors.
Compliance with spatial fishing regulations (e.g., marine protected areas, fishing closures) is one of the most important, yet rarely measured, determinants of ecological recovery. We used aerial observations of recreational fishing events from creel surveys before, during, and after 77 Rockfish Conservation Areas (RCAs) were established in British Columbia, Canada. There was no evidence of a change in fishing effort in 83% of the RCAs, and effort in five RCAs increased after establishment. Fishing effort in open areas adjacent to the RCAs declined with time and was higher than effort in the RCAs in all 3 years. Next, we used compliance data for 105 RCAs around Vancouver Island to model the drivers of compliance. Compliance was related to the level of fishing effort around the RCA, the size and perimeter-to-area ratio of RCAs, proximity to fishing lodges, and the level of enforcement. Noncompliance in RCAs may be hampering their effectiveness and impeding rockfish recovery. Education and enforcement efforts to reduce fishing effort inside protected areas are critical to the recovery of depleted fish stocks.
This study reports plastic debris pollution in the deep-sea based on the information from a recently developed database. The Global Oceanographic Data Center (GODAC) of the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) launched the Deep-sea Debris Database for public use in March 2017. The database archives photographs and videos of debris that have been collected since 1983 by deep-sea submersibles and remotely operated vehicles. From the 5010 dives in the database, 3425 man-made debris items were counted. More than 33% of the debris was macro-plastic, of which 89% was single-use products, and these ratios increased to 52% and 92%, respectively, in areas deeper than 6000 m. The deepest record was a plastic bag at 10898 m in the Mariana Trench. Deep-sea organisms were observed in the 17% of plastic debris images, which include entanglement of plastic bags on chemosynthetic cold seep communities. Quantitative density analysis for the subset data in the western North Pacific showed plastic density ranging from 17 to 335 items km−2 at depths of 1092–5977 m. The data show that, in addition to resource exploitation and industrial development, the influence of land-based human activities has reached the deepest parts of the ocean in areas more than 1000 km from the mainland. Establishment of international frameworks on monitoring of deep-sea plastic pollution as an Essential Ocean Variable and a data sharing protocol are the keys to delivering scientific outcomes that are useful for the effective management of plastic pollution and the conservation of deep-sea ecosystems.
Using density measurements derived by SCUBA diving, we have verified that research angling catch per unit of effort (CPUE) is a useful measurement of the relative abundance of nearshore reef species when the appropriate habitat is targeted. We found a strictly proportional relationship between lingcod and copper rockfish CPUE and density using a ranged major axis regression. This relationship did not hold for quillback rockfish since this study did not target their preferred depth range; nor for kelp greenling. Researchers must be aware of such limitations when using CPUE as a measure of relative abundance.
Environmental education for children is one of the fundamental tools required to reverse the degradation of our environment and the biodiversity erosion. Currently coral reefs are part of the vulnerable ecosystems which are most threatened by human activities and climate change. Responding to these pressures demands decisions at multiple scales, based on solid knowledge of coral reefs but also on strengthened awareness to build adaptive management solutions. Here we evaluate the impact of an environmental awareness campaign for children using a teaching toolbox developed by scientists (MARECO “The Coral Reef In Our Hands”). To assess this impact before and after using the toolbox, we analyzed the evolution of children's representations of coral reefs through drawings. This study was carried out in New Caledonia, focusing on five elementary schools in different social and cultural contexts (urban, rural and coastal). Two hundred and forty-eight drawings were made by children. The drawings were analyzed quantitatively using multivariate statistical analyses which reveals a diversity of representations in children with diverse sociocultural profiles, but also between schools, emphasizing that relationships with nature and marine environment vary according to direct and indirect experiences related to reefs. Furthermore, our results pointed out relevant differences in coral reef representations before and after the use of MARECO, particularly regarding their knowledge of reef biodiversity associated with multicolored organisms and the connection of coral reef with environment, the number of colors being used as a proxy of this holistic vision developed by children. These results point out the performance of MARECO as a playful tool to transfer scientific knowledge to children. Coral reef conservation is intimately linked to an awareness in young generations of the environmental challenges of tomorrow. To be agents of change in a sustainable world, children must be engaged in a fun, rigorous, action-oriented and socially responsible learning process such as the ones developed in participatory approaches.
Between 2004 and 2007, Fisheries and Oceans Canada undertook a management action to conserve overfished populations of Inshore Rockfishes by designating 164 Rockfish Conservation Areas (RCAs) closed to most recreational and commercial fishing. However, no research has yet assessed the effectiveness of the RCA network at promoting groundfish population recoveries. We surveyed the fish communities of 35 RCAs and adjacent unprotected areas in southern British Columbia using a remotely operated vehicle (ROV) between 2009 and 2011. We investigated the effect of protection and habitat on fish densities for six species or species groups (Quillback, Yelloweye, Greenstriped Rockfish, Kelp Greenling, Lingcod and all Inshore Rockfish combined) on transects inside and outside of RCAs. Habitat features such as percent rocky substrates and depth influenced fish density while reserve status did not. Next, we calculated habitat-based average densities and used the mean log response ratio (RR) of the density inside to outside of RCAs to determine if the amount of fishing outside the RCA, previous fishing history, the age, area or perimeter to area ratio influenced population recovery. Few positive reserve effects were apparent for any species/group. No clear patterns of RR with age were found for the RCAs, which ranged from 3 to 7 years old at the time of sampling (mean = 4.6). In addition, the intensity of fishing, size, and perimeter-to-area ratio failed to explain RR for most species. There were also no differences in size structure (length) of fish between RCAs and unprotected areas. The results give little indication that demersal fish populations have recovered inside the RCA system. Ongoing monitoring is essential to assess population recovery over time and evaluate the RCAs in terms of criteria such as habitat quality, habitat isolation and the level of compliance in order to enhance their effectiveness.
Many analyses of fishery recovery have demonstrated the potential biological and economic benefits of management reform, but few have compared these to the associated costs of management upgrades, which can be substantial. This study aims to determine if the projected economic benefits of management reform outweigh the increases in management costs required to achieve those benefits. To answer this question, we developed a database of country-level fisheries management costs and use those to estimate the country-level costs of management changes. We use this framework to compare estimates of future costs of management upgrades against their economic benefits in terms of profit. Results indicate that for most nations, including the top 25 fishing nations, management upgrades outweigh their associated costs. This result is robust to a number of alternative assumptions about costs. Results also suggest that stronger reforms such as rights-based management, although sometimes more expensive to implement, can lead to greater net economic benefits compared to alternatives.
San Francisco Bay, the largest estuary on the Pacific Coast of North America, is heavily encroached by a metropolitan region with over 7 million inhabitants. Urban development and infrastructure, much of which built over landfill and at the cost of former baylands, were placed at very low elevations. Sea level rise (SLR) poses a formidable challenge to these highly exposed urban areas and already stressed natural systems.
“Green”, or ecosystem-based, adaptation is already on the way around the Bay. Large scale wetland restoration projects have already been concluded, and further action now often requires articulation with the reinforcement of flood defense structures, given the level of urban encroachment. While levee setback, or removal, would provide greater environmental benefit, the need to protect urban areas and infrastructure has led to the trial of ingenious solutions for promoting wetland resilience while upgrading the level of protection provided by levees.
We analyzed the region’s environmental governance and planning structure, through direct observation, interviews with stakeholders, and study of planning documents and projects. We present two examples where actual implementation of SLR adaptation has led, or may lead to, the need to revise standards and practices or require uneasy choices between conflicting public interests.
Among the region’s stakeholders, there is an increasing awareness of the risks related to SLR, but the institutional arrangements are complex, and communication between the different public agencies/departments is not always as streamlined as it could be. Some agencies and departments need to adapt their procedures in order to remove institutional barriers to adaptation, but path dependence is an obstacle. There is evidence that more frank and regular communication between public actors is needed. It also emphasizes the benefits of a coordination of efforts and strategies, something that was eroded in the transition from central-government-led policies to a new paradigm of local-based adaptive governance.
Solid-liquid filtration is a ubiquitous process found in industrial and biological systems. Although implementations vary widely, almost all filtration systems are based on a small set of fundamental separation mechanisms, including sieve, cross-flow, hydrosol, and cyclonic separation. Anatomical studies showed that manta rays have a highly specialized filter-feeding apparatus that does not resemble previously described filtration systems. We examined the fluid flow around the manta filter-feeding apparatus using a combination of physical modeling and computational fluid dynamics. Our results indicate that manta rays use a unique solid-fluid separation mechanism in which direct interception of particles with wing-like structures causes particles to “ricochet” away from the filter pores. This filtration mechanism separates particles smaller than the pore size, allows high flow rates, and resists clogging.