Management of marine ecosystems increasingly demands comprehensive and quantitative assessments of ocean health, but lacks a tool to do so. We applied the recently developed Ocean Health Index to assess ocean health in the relatively data-rich US west coast region. The overall region scored 71 out of 100, with sub-regions scoring from 65 (Washington) to 74 (Oregon). Highest scoring goals included tourism and recreation (99) and clean waters (87), while the lowest scoring goals were sense of place (48) and artisanal fishing opportunities (57). Surprisingly, even in this well-studied area data limitations precluded robust assessments of past trends in overall ocean health. Nonetheless, retrospective calculation of current status showed that many goals have declined, by up to 20%. In contrast, near-term future scores were on average 6% greater than current status across all goals and sub-regions. Application of hypothetical but realistic management scenarios illustrate how the Index can be used to predict and understand the tradeoffs among goals and consequences for overall ocean health. We illustrate and discuss how this index can be used to vet underlying assumptions and decisions with local stakeholders and decision-makers so that scores reflect regional knowledge, priorities and values. We also highlight the importance of ongoing and future monitoring that will provide robust data relevant to ocean health assessment.
The vastness of the ocean came sharply into focus nearly 50 years ago, when the Apollo missions produced the first images of our overwhelmingly blue planet from space. More recently, a number of United Nations reports and peer-reviewed scientific studies have underlined the interconnectedness between the planetary climate and ocean systems, and the central role that the ocean is playing in protecting us from the impacts of climate change. Yet, despite this heightened awareness, the ocean remains chronically undervalued, poorly managed and inadequately governed.
This is particularly true of the high seas, the 64% of the total surface area of the ocean that is beyond the jurisdiction of any State. The high seas also provides a critical life-support function for areas within the national jurisdiction of coastal States (exclusive economic zones or EEZs) and what happens on the high seas can and does have a significant impact on the ecological health and productivity of EEZs.
When the United Nations Convention on the Law of the Sea (UNCLOS) – the ‘constitution for the ocean’ – was negotiated, the high seas was protected by its inaccessibility. Today, there is virtually nowhere that industrial fishing vessels cannot reach, offshore oil and gas drilling is extending further and deeper every year, and deep sea mineral extraction is fast becoming a reality. The concept of the ‘freedom of the high seas’ guaranteed in the Convention once conjured up images of adventure and opportunity, but it is now driving a relentless ‘tragedy of the commons’, characterised by the depletion of fish stocks and other precious marine resources. The freedom is being exploited by those with the money and ability to do so, with little sense of responsibility or social justice.
People have lived near the ocean for millennia and maritime communities have always recognised the importance of the ocean and made it the centre of their economies and cultures. While it was living ocean resources that first drew people to the sea – and ocean fisheries and aquaculture today provide food for billions of people as well as livelihoods for millions – today we are increasingly aware of the less visible yet even more vital role the ocean plays in regulating the life-giving systems of our planet. It is the great biological pump at the heart of global atmospheric and thermal regulation and the driver of the water and nutrient cycles.
High seas ecosystems are estimated to be responsible for nearly half of the biological productivity of the entire ocean. The global ocean produces almost half of all the oxygen we breathe and absorbs more than a quarter of the carbon dioxide we emit into the atmosphere. More than 90% of the heat trapped in the Earth system by greenhouse gas emissions is stored in the ocean, providing a buffer against the full impacts of climate change on land; but this is having alarming consequences on ocean life and is perhaps the largest unseen environmental disaster of our time.
The ocean is, in essence, the kidney of our planet, keeping its systems healthy and productive. But the ability of the ocean to continue to provide these essential ecosystem services is being compromised as rising temperatures reduce its oxygen-carrying capacity. The increasing uptake of carbon dioxide is causing ocean acidification, and unprecedented changes in chemical and physical conditions are already impacting the distribution and abundance of marine organisms and ecosystems. The very life of the global ocean, from the smallest phytoplankton to the largest of the great whales, is being impacted.
The international community has expended a tremendous amount of political capital and diplomatic effort on establishing policy commitments aimed at reversing ocean degradation. Unfortunately, there remains a huge gap between the commitments expressed in various policy documents and the willingness or ability of States to implement them. For example, the Heads of State and Government at the 2002 World Summit on Sustainable Development (WSSD) said that they would establish a representative network of marine protected areas (MPAs) by 2012, but by the time of the 2012 Rio+20 Summit it was evident that little progress had been made towards meeting this target, especially beyond coastal areas. Today, MPAs cover less than 1% of the high seas.
The conclusion we have come to is that the current governance system for the management of human activities impacting the high seas is no longer fit for purpose and cannot ensure longterm sustainability or equity in resource allocation, nor create the conditions for maximising economic benefits from the high seas. UNCLOS has proven itself particularly slow in responding to new challenges, not least when it comes to improving the management of growing threats and risks to biodiversity, ecosystems and fishery resources in the high seas, a need that has been widely recognised since at least 2002.
By understanding the drivers of decline individually and together, we have come to understand that what is needed is an integrated rescue package which can deliver ocean restoration when undertaken as a whole. We have considered equity, development and sustainability, and economic as well as intrinsic values. We have thought about the roles of consumers, intermediaries and markets, politicians, direct users and indirect beneficiaries.
In 2013, the Aspen Institute published The Ocean Community Report, a study based on a 2012 roundtable discussion with oceans leaders at Fort Baker, California on the state of ocean conservation, as well as two research papers on marine protection advocacy, policy and management.
The report’s recommendations suggested opportunities for improving the effectiveness of collaboration among ocean conservation advocacy groups, funders and policymakers, including taking advantage of the synergies between conservation tools, reframing ocean conservation as a solution to other national issues, and promoting win-win conservation opportunities.
Building on this report, a second gathering of oceans experts was convened one year later at Aspen Wye River to assess the steps required for scaling investment in and deployment of ocean conservation tools in both small-scale coastal fisheries and large-scale MPAs. This roundtable served as a platform for the community to discuss and develop its alignment of conservation priorities with socioeconomic goals and advance innovative conservation financing opportunities.
Based on these 2013 discussions at Wye River, and Aspen’s Ocean Community Report, the following recommendations have been forwarded for continued reflection and prioritization by the ocean community:
- Public-Private Partnerships on ocean conservation should be built around the needs of local governments and communities—rather than solely around MPAs, MSP or biodiversity—and focus on specific local fisheries problems, food security challenges and economic needs. This approach will get at the heart of the particular goals in which that country will be more willing to invest public funds. The global replication of successful marine protection requires the development of a clear and strong value proposition, such that the conservation community becomes an agent for establishing the systems and benefits that local leaders themselves want. Moving forward, the conservation community must apply a nuanced understanding of strategies for inspiring local leadership in this way, especially in the case of initially unreceptive governments.
- Scaling marine protection to the levels required for global impact will require significant partnership with not only government but with the private sector, specifically with corporations. Where MPAs, MSP or TURFs may gain little traction, developing a stronger economic development approach of selling a specific goal (in this case, long-term conservation of marine resources) will help coastal communities to understand the product being offered and better recognize its value. The private sector—especially corporations dependent on coastal resilience—is particularly interested in the sustainability of small scale artisanal fisheries, and so will lead the way in creating sustainable ocean economies by investing in coastal resilience and implementing technologies that make enhanced marine protection and monitoring possible.
- An innovative and landscape-changing approach to replicating marine conservation is coordination by NGOs or funders using a subcontractor model of partnership and coordination, whereby a single NGO or funder entity develops the demand and commitment from local political leadership, and then delivers on the goals by establishing partnerships with those best prepared to achieve specific goals.
The industrialisation and overuse of the high seas jeopardises the natural wealth of their ecosystems and the services they provide to people. Fishing and shipping continue to inflict harm on high-seas ecosystems. Mining for minerals and new sources of fossil fuels will likely increase the industrial use of the high seas and will further damage their ecosystems. At the same time, the governance of the high seas is fragmented, with different international institutions focusing on specific industrial activities, places, or even different parts of the ecosystems. For instance, weak fisheries governance in the high seas has led to ad hoc regulation that varies from place to place. The result has been widespread overfishing.
There is growing evidence that the ecosystem services provided by the high seas are of high social and economic value. The evidence also is clear that poor management of human activities on the high seas has eroded the natural wealth and productivity of high-seas ecosystems with negative economic and social consequences for all of us.
We examine 15 important ecosystem services provided by the high seas. These fall into the categories of provisioning services (seafood; raw materials; genetic resources; medicinal resources; ornamental resources), regulating services (air purification; climate regulation; waste treatment; biological control) habitat services (lifecycle maintenance; gene pool protection) and cultural services (recreation and leisure; aesthetic information; information for culture, art, design and for cognitive development). The quantity and quality of ecosystem services depend directly on both the living (e.g. animals, algae, microorganisms) and non-living (e.g. the shape and structure of the seabed) components of the marine ecosystems of the high seas.
To understand the potential value of high-seas ecosystem services, we describe and quantify, when possible, the provision and general nature of values provided by these 15 types of ecosystem services. We put these values in the context of the costs of improved governance and management of human activities in the high seas with a particular focus on improved marine protection.
Few ecosystem services in the high seas can be accurately valued given currently available information. We lack scientific information about the provision and use of most high-seas ecosystem services and their quantity and nature, and even lack knowledge regarding how and where, precisely, they are produced. The high seas support economically important species that may swim, migrate or drift well beyond the physical boundaries of the high seas. This makes it difficult to disentangle the contribution of high-seas ecosystems to the services that are produced in the high seas but are enjoyed elsewhere – sometimes thousands of kilometres away. Many high-seas ecosystem services are not enjoyed directly in all contexts. Instead, in some contexts, many play an intermediate role in the creation of ecosystem services elsewhere (e.g. high-seas ecosystems support prey that are consumed by commercially important fish species which are harvested elsewhere). Clearly, there is the need for more and better science on the provision and value of high-seas ecosystem services.
We provide estimates of the economic value of two important high-seas ecosystem services: carbon storage and fisheries. Carbon is stored by high-seas ecosystems as part of naturally occurring processes in which marine organisms convert sunlight and carbon dioxide into energy and biological production. We estimate that high-seas ecosystems are responsible for nearly half of the biological productivity of the global ocean. While the science of carbon sequestration in the high seas is still evolving, we estimate that nearly half a billion tonnes of carbon, the equivalent of over 1.5 billion tonnes of carbon dioxide, are captured and stored by high-seas ecosystems annually. Based on current estimates of the economic cost of additional carbon in the atmosphere (i.e. the social cost of carbon), we find that the value of carbon storage by high-seas ecosystems ranges between US$74 billion and US$222 billion annually.
A new report on Arctic information and communication needs (“Gap Analysis Report”) has been released as part of the Strategic Environmental Impact Assessment of development of the Arctic Preparatory Action project, funded by DG Environment of the European Commission. The Gap Analysis Report was led by Ecologic Institute in partnership with the European Science Foundation, National Research Council of Italy, Sámi Education Institute, and Tromsø Centre for Remote Sensing.
The report identifies, analyzes, and illustrates the Arctic information needs of stakeholders and policy-makers and offers recommendations on ways to improve knowledge and to improve two-way communication between information providers and users. It highlights information and communication gaps and major Arctic trends throughout a number of thematic areas and human needs in the Arctic. The Gap Analysis Report also assesses how an EU Arctic Information Centre (EUAIC) could improve information provision and communication.
“The Gap Analysis Report demonstrates that Arctic stakeholders not only desire new information, but also seek better, coordinated access to existing information sources, which a network of expert institutes operating as an EU Arctic Information Centre could help facilitate,” said Elizabeth Tedsen, Fellow at Ecologic Institute.
“The Arctic has become of global interest during the past few years, and it is important that images, decisions, and policies regarding the development of the region are based on best available information,” commented Professor Paula Kankaanpää, Director of the Arctic Centre and Principal Investigator on the Preparatory Action.
While the report’s recommendations in the context of the Preparatory Action were necessarily limited due to its broad thematic focus, it should be seen as a building block for future efforts, including for subject-specific recommendations that draw from the wealth of knowledge of Arctic stakeholders.
Shallow-water estuarine and coastal marine habitats in the Gulf of Maine comprise some of the most productive habitats in the northeastern United States and have been identified as Essential Fish Habitat (EFH)1 for many species of importance to commercial and recreational fisheries. However, these near-shore habitats are also the most vulnerable to human disturbances due to their proximity to coastal population centers. The purpose of this report is to describe the importance of shallow-water habitats (0-10 meters) for spawning, feeding, and growth to maturity for 16 fish and invertebrate species in the Gulf of Maine based on a literature review. The species include a mix of federally managed fishery species, state-managed fishery species and other species that are important members of the shallow-water marine ecosystem. Habitat use was assessed for individual life history stages of each species in eight shallow-water benthic habitats: mud, sand, gravel/cobble, boulder, eelgrass, macroalgae, salt marsh channels, and shellfish beds. Habitat use scores (0 = absent, 1 = present, and 2 = common or abundant) were assigned to each benthic life stage of each species known to occur in depths less than 10 meters. Scores were then summarized for all species in each habitat type. According to this evaluation, shallow-water habitats in the Gulf of Maine are used by young-of-the-year juveniles of all 16 species. Additionally, older juveniles of 12 species and adults of 11 species also rely on these habitats. Nine of the sixteen species spawn in one or more of these habitats. Further analysis shows that sand and gravel/cobble habitats are used by the most species and life stages, followed by mud, eelgrass, macroalgae, boulder, salt marsh channels, and shell (mussel) beds. Shallowwater habitats in the Gulf of Maine provide valuable ecological services for a variety of species. Mud, sand, gravel/cobble, and vegetated habitats are particularly important as juvenile nursery grounds for species such as Atlantic cod, Atlantic tomcod, American lobsters, winter flounder, soft-shell clams, and blue mussels.
An important goal of this guidance is to help practitioners and policy-makers understand what constitutes “good” climate adaptation, how to recognize those characteristics in existing work, as well as how to design new interventions when necessary. Part I of this guide focuses on exploring climate-smart conservation, and offers a structured process for putting it into practice. To this end, we define “climate-smart conservation” as:
The intentional and deliberate consideration of climate change in natural resource management, realized through adopting forward-looking goals and explicitly linking strategies to key climate impacts and vulnerabilities.
Determining what represents appropriate and relevant adaptation is highly context specific, but there are a number of attributes that can help distinguish when and whether climate considerations are suitably being incorporated into conservation work. To assist practitioners in making that distinction, we have identified the following set of key characteristics that collectively define a climate-informed approach to conservation.
Outbreaks of Acropora and Diadema diseases in the 1970s and early 1980s, overpopulation in the form of too many tourists, and overfishing are the three best predictors of the decline in Caribbean coral cover over the past 30 or more years based on the data available. Coastal pollution is undoubtedly increasingly significant but there are still too little data to tell. Increasingly warming seas pose an ominous threat but so far extreme heating events have had only localized effects and could not have been responsible for the greatest losses of Caribbean corals that had occurred throughout most of the wider Caribbean region by the early to mid 1990s.
In summary, the degradation of Caribbean reefs has unfolded in three distinct phases:
- Massive losses of Acropora since the mid 1970s to early 1980s due to WBD. These losses are unrelated to any obvious global environmental change and may have been due to introduced pathogens associated with enormous increases in ballast water discharge from bulk carrier shipping since the 1960s.
- Very large increase in macroalgal cover and decrease in coral cover at most overfished locations following the 1983 mass mortality of Diadema due to an unidentified and probably exotic pathogen. The phase shift in coral to macroalgal dominance reached a peak at most locations by the mid 1990s and has persisted throughout most of the Caribbean for 25 years. Numerous experiments provide a link between macroalgal increase and coral decline. Macroalgae reduce coral recruitment and growth, are commonly toxic, and may induce coral disease.
- Continuation of the patterns established in Phase 2 exacerbated by even greater overfishing, coastal pollution, explosions in tourism, and extreme warming events that in combination have been particularly severe in the northeastern Caribbean and Florida Keys where extreme bleaching followed by outbreaks of coral disease have caused the greatest declines.
The walleye pollock (Gadus chalcogrammus) fishery in the Bering Sea is one of the largest fisheries in the world. The North Pacific Fishery Management Council (NPFMC) provides management advice for this fishery, including the development of measures to minimize salmon bycatch to the extent practicable, one of the stated objectives of the US Magnuson–Stevens Fishery Conservation and Management Act National Standard Guidelines. Salmon have a unique cultural and nutritional importance in the State of Alaska and are the subject of fully allocated mixed commercial, recreational, and subsistence fisheries. Chinook salmon (Oncorhynchus tshawytscha) stocks in Alaska have been declining for the last decade, and all sources of mortality are being considered to help in rebuilding stocks. Given the extensive scientific National Marine Fisheries Service observer data collection programme, the NPFMC has developed bycatch management measures that place limits by fishery sector on the allowable catch of Chinook salmon. Part of this programme includes industry-proposed incentive programmes designed to encourage lower bycatch. Evaluating the efficacy of the new measures poses a number of challenges, particularly in light of changing ocean conditions (perhaps affecting the degree of overlap between pollock and salmon). In this study, data on pre- and post-programme implementation were evaluated to determine if the programme is meeting stated goals and objectives or if modifications are needed. These evaluations included consideration of fleet-level bycatch numbers and rates, seasonality of bycatch by sector, and individual vessel bycatch rates. Results suggest that revised management regulations appear to have resulted in reduced bycatch of salmon overall. Also, lower bycatch rates seem to reflect changing behaviour in response to new management measures. However, the extent to which the programme is effective at the vessel level remains difficult to ascertain without explicit vessel-specific benchmarks developed for evaluating programme efficacy.
Invasive non-native species frequently occur in very high densities. When such invaders present an economic or ecological nuisance, this biomass is typically removed and landfill is the most common destination, which is undesirable from both an economic and ecological perspective. The zebra mussel, Dreissena polymorpha, has invaded large parts of Europe and North America, and is routinely removed from raw water systems where it creates a biofouling nuisance. We investigated the suitability of dried, whole zebra mussels as a supplement to poultry feed, thus providing a more attractive end-use than disposal to landfill. Measurable outcomes were nutrient and energy composition analyses of the feeds and production parameters of the birds over a 14 day period. Zebra mussels were a palatable feed supplement for chickens. The mussel meal contained high levels of calcium (344.9 g kg−1), essential for egg shell formation, which was absorbed and retained easily by the birds. Compared with standard feed, a mussel-supplemented diet caused no significant effects on production parameters such as egg weight and feed conversion ratio during the study period. However, protein and energy levels in the zebra mussel feed were much lower than expected from the literature. In order for zebra mussels to be a viable long-term feed supplement for poultry, flesh would need to be separated from the shells in an economically viable way. If zebra mussels were to be used with the shells remaining, it seems that the resultant mussel meal would be more suitable as a calcium supplement.
Modern resource management faces trade-offs in the provision of various ecosystem goods and services to humanity. For fisheries management to develop into an ecosystem-based approach, the goal is not only to maximize economic profits, but to consider equally important conservation and social equity goals. We introduce such a triple-bottom line approach to the management of multi-species fisheries using the Baltic Sea as a case study. We apply a coupled ecological-economic optimization model to address the actual fisheries management challenge of trading-off the recovery of collapsed cod stocks versus the health of ecologically important forage fish populations. Management strategies based on profit maximization would rebuild the cod stock to high levels but may cause the risk of stock collapse for forage species with low market value, such as Baltic sprat (Fig. 1A). Economically efficient conservation efforts to protect sprat would be borne almost exclusively by the forage fishery as sprat fishing effort and profits would strongly be reduced. Unless compensation is paid, this would challenge equity between fishing sectors (Fig. 1B). Optimizing equity while respecting sprat biomass precautionary levels would reduce potential profits of the overall Baltic fishery, but may offer an acceptable balance between overall profits, species conservation and social equity (Fig. 1C). Our case study shows a practical example of how an ecosystem-based fisheries management will be able to offer society options to solve common conflicts between different resource uses. Adding equity considerations to the traditional trade-off between economy and ecology will greatly enhance credibility and hence compliance to management decisions, a further footstep towards healthy fish stocks and sustainable fisheries in the world ocean.
Although the importance of addressing ecosystem service benefits in regional land use planning and decision-making is evident, substantial practical challenges remain. In particular, methods to identify priority areas for the provision of key ecosystem services and other environmental services (benefits from the environment not directly linked to the function of ecosystems) need to be developed. Priority areas are locations which provide disproportionally high benefits from one or more service. Here we map a set of ecosystem and environmental services and delineate priority areas according to different scenarios. Each scenario is produced by a set of weightings allocated to different services and corresponds to different landscape management strategies which decision makers could undertake. Using the county of Cornwall, U.K., as a case study, we processed gridded maps of key ecosystem services and environmental services, including renewable energy production and urban development. We explored their spatial distribution patterns and their spatial covariance and spatial stationarity within the region. Finally we applied a complementarity-based priority ranking algorithm (zonation) using different weighting schemes. Our conclusions are that (i) there are two main patterns of service distribution in this region, clustered services (including agriculture, carbon stocks, urban development and plant production) and dispersed services (including cultural services, energy production and floods mitigation); (ii) more than half of the services are spatially correlated and there is high non-stationarity in the spatial covariance between services; and (iii) it is important to consider both ecosystem services and other environmental services in identifying priority areas. Different weighting schemes provoke drastic changes in the delineation of priority areas and therefore decision making processes need to carefully consider the relative values attributed to different services.
This dissertation work presents a novel method for addressing system uncertainty to improve management of a small-scale fishery in St. Croix, United States Virgin Islands. Using fishers' ecological knowledge (FEK), this research examines existing perspectives and biases through the Q-Method to identify regulatory inefficiencies in the management framework and strengthen the rationale for including fishers into the management process, develops a coupled behavior-economics model to predict the likelihood of fishing the preferred grounds under a range of physical and regulatory conditions, establishes a baseline assessment of a spawning aggregation of mutton snapper following sixteen years of protection through a no-take marine protected area, and conducts a discrete choice method test to examine likely public support for FEK-based proposed regulatory alternatives. This work contributes to an under-studied and much-needed area of fisheries management, that of incorporating socioeconomic motivations within an ecosystem-based framework. As fisheries management efforts begin to embrace ecosystem-based approaches, the need for understanding and incorporating the knowledge and behavior of fishers into management has never been greater. Ecological goals of fishery sustainability and continued habitat function cannot be achieved without first understanding how fishers view and respond to any regulatory environment and then developing a framework that achieves the greatest support for those regulations. The time has come for incorporating FEK into ecosystem-based fisheries management.
Hong Kong’s pink dolphins are majestic, intelligent, and beautiful. Unfortunately, Hong Kong’s coastal waters are no longer suitable for pink dolphin populations. Vessel traffic, water pollution, land reclamation projects, and localized constructionblasting activity all contribute to the declining stability of their habitat. These destructive impacts on the marine environment derive from Hong Kong’s generally inadequate political and regulatory protections, increased tourist use of polluting river boats to view the dolphins, ambivalent local perceptions of the problem, and a growing human population, which together make environmental protection increasingly more difficult. Despite this unequivocally bleak future, legal tools exist that can help improve and preserve their habitat. Although litigation under Hong Kong’s environmental statutes is rare, bringing suit under existing laws can create meaningful change for the pink dolphin. The Wild Animals Protection Ordinance contains provisions that may lead to a prohibition of local vessels navigating through dolphin marine habitat.
In order to carry out this litigation strategy and others like it, parties need more exposure and a better understanding of the legal actions available to them. This comment demonstrates how parties can successfully litigate under the Wild Animals Protection Ordinance for the protection of pink dolphins despite Hong Kong’s current political climate. Part II describes the Hong Kong pink dolphin and major threats to dolphin populations. Part III analyzes Hong Kong’s history of delayed proactivity, regulation, litigation, and enforcement of environmental and animal welfare matters. Part IV develops a potential case under the Wild Animals Protection Ordinance for better protection of Hong Kong’s pink dolphins. Part V summarizes other legal avenues available for protection of pink dolphins and other marine species. Finally, Part VI concludes by encouraging government agencies and private parties to bring novice environmental cases under existing legislation and to press for statutory amendments where necessary to better protect Hong Kong’s natural resources, habitat, and species.
Fisheries science often uses population models that assume no external recruitment, but nearshore marine populations harvested on small scales of <200 km often exhibit an unknown mix of self-recruitment and recruitment from external sources. Since empirical determination of self-recruitment vs. external recruitment is difficult, we used a modeling approach to examine the sensitivity of fishery management priorities to recruitment assumptions (self [closed], external [open]) in a local population of harvested giant clams (Tridacna maxima) on Mo'orea, French Polynesia. From 2006 to 2010, we measured growth, fecundity, recruitment, and survival (resulting from natural and fishing mortality). We used these data to parameterize both a closed (complete self-recruitment) and an open (no self-recruitment) integral projection model (IPM), and then calculated elasticities of demographic rates (growth, survival, recruitment) to future population abundance in 20 years. The models' lowest projected abundance was 93.4% (95% CI, [86.5%, 101.8%]) of present abundance, if the local population is entirely open and the present level of fishing mortality persists. The population will exhibit self-sustaining dynamics (1 ≤ λ ≤ 1.07) as for a closed population if the ratio of self-recruits per gram of dry gonad is >0.775 (equivalent to 52.85% self-recruitment under present conditions). Elasticity analysis of demographic parameters indicated that future abundance can most effectively be influenced by increasing survival of mid-sized clams (∼80–120 mm) if the population is self-sustaining, and by increasing survival of juvenile clams (∼40–70 mm) if the population is non-self-sustaining (as for an open population). Our results illustrate that management priorities can vary depending on the amount of self-recruitment in a local population.
Oceanic dispersal and connectivity have been identified as crucial factors for structuring marine populations and designing marine protected areas (MPAs). Focusing on larval dispersal by ocean currents, we propose an approach coupling Lagrangian transport and new tools from Network Theory to characterize marine connectivity in the Mediterranean basin. Larvae of different pelagic durations and seasons are modeled as passive tracers advected in a simulated oceanic surface flow from which a network of connected areas is constructed. Hydrodynamical provinces extracted from this network are delimited by frontiers which match multiscale oceanographic features. By examining the repeated occurrence of such boundaries, we identify the spatial scales and geographic structures that would control larval dispersal across the entire seascape. Based on these hydrodynamical units, we study novel connectivity metrics for existing reserves. Our results are discussed in the context of ocean biogeography and MPAs design, having ecological and managerial implications.
California kelp forests are highly productive and species rich ecosystems. However, ecosystem-wide consequences of fishing higher tropic levels (fishes) and the effect of climate on primary producers such as the giant kelp, Macrocystis pyrifera, are not well understood. I develop and apply mass-balanced ecological network models, Ecopath with Ecosim, to explore separately how fishing and the dynamics of giant kelp influence ecosystem functions (e.g., species interactions, biomass dynamics), structure (e.g., the distribution of biomass density among species or species groups) and their dynamics. Faced with the difficulty of synthesizing information required to construct these models, I develop and apply an online database (http://kelpforest.ucsc.edu/) to facilitate the accessibility of such information. It is the first online database designed specifically to inform development of ecological network models. To explore ecosystem-wide effects of fishing in giant kelp forests, I examine (i) the extent to which changes in species interactions and biomass of nodes caused by fishing extend across the ecological network, how these changes vary with (ii) levels of fishing mortality, (iii) fishing of six different species of fishes, and (iv) when all six species are fished simultaneously. Results suggest that fished species differ markedly in the extent to which species interactions and biomass densities are altered across the ecosystem and these responses vary with different levels of fishing mortality. I also used the models to predict ecosystem-wide responses to different dynamics of giant kelp biomass. I test the hypotheses that different scenarios of dynamics of giant kelp biomass will influence (i) total network biomass, (ii) distribution of biomass density across nodes, (iii) temporal variation in biomass density of nodes, and (iv) how this variation differs among trophic levels. Results suggest that both the mean and the variability of giant kelp biomass alter the direction and magnitude of change in total network biomass. Variation is greater for lower trophic levels. Although all inferences of these models are based solely on trophic interactions, they illustrate the value of ecosystem models to generate hypotheses and predictions of ecosystem responses to one or more changes in kelp forests.
This work looks into the conservation of South American sea lions (SSL), Otaria byronia by advancing a process of Marine Protected Area (MPA) design targeted for reproductive females during the first weeks of lactation. Focusing on protection of a single species may result in the establishment of a more comprehensive and ecologically functional system for management. SSL is distributed in the Atlantic and the Pacific coasts of South America. Along the coast of the Argentine Patagonian coast, 73 colonies were described, 42 % of which are reproductive. Breeding females give birth during the austral summer (January) and lactation lasts ca. one year. Critical to the annual cycle are the few weeks after birth, when mothers spend 2-3 days nursing and a similar or longer time at sea foraging, while pups remain alone on shore. Satellite tracking and dive recording instruments indicate that females are either coastal or pelagic in their feeding habits, but the latter travel relatively short distances from colony (mean 152 km). SSL are bottom foragers that dive to maximum depths of approximately 80 m. Optimizing travel and foraging time is critical for these animals, as pups left alone fast and are threatened by both starvation and being accidentally crushed by fighting adult males. Foraging areas overlap with fishing grounds, sea lions are caught in fishing gear and competition for food cannot be ignored. Yet, although 20 of the 31 existing breeding colonies are within coastal protected areas, none of the foraging areas have been considered for protection to minimize the consequences of interactions with fisheries. This work draws from very limited data to advance a process of design of Marine Protected Areas that is eminently practical, thus affordable to government wildlife administrators. I selected the most important colonies, based on location and abundance, integrated satellite locations at sea, analyzed potential associations with physical variables, and proposed criteria to decide important marine areas based on distribution at sea. Finally, I estimated the cost for fisheries to comply with the proposed conservation intervention scenarios. Foraging distribution did not follow a pattern consistent with physical oceanographic variables (sea surface temperature, productivity, bathymetry and seafloor composition) to guide conservation intervention. Bathymetry was the best proxy to help in the design of protected areas. Most of the conservation scenarios based on distribution at sea of lactating females did not strongly overlap with fisheries to justify conservation intervention. The colonies that did, however, involved the largest breeding colonies of Argentine Patagonia and Uruguay. In a context of closing the fisheries for the area of overlap and compensate for the loses during one month, I estimate a conservation cost of 2-3 million dollars, as the impact is on the most profitable of all Argentine Patagonian fisheries, targeting Argentine red shrimp, Pleoticus muelleri. I conclude that management that includes MPAs for this species requires a priori spatial planning considerations. Once a fishery is operational, the costs for conservation will not be affordable for the administrators. I identified some areas where an a priori approach would be practical, effective and feasible.
Environmental conflicts in coastal areas are determined by the interaction of global and local phenomena. Identifying the factors characterising the evolution of conflicts in relation to spatial dynamics is complex. Analysing related data and interpreting the results necessitate the use of methods that take this complexity into account. Artificial Neural Networks (ANN) have been used to accomplish this task. Although ANN have been widely implemented in physics, natural science and engineering, their application in spatial and social science is still in an early stage.
We present the results of a study concerning land use conflict in the area of Civitavecchia, the main harbour of the Rome metropolitan area. Local environmental issues are air pollution from a large thermal power plant, the movement of ferries, cruise ships, and increased individual commuting. We simulate alternative policy scenarios for the conflict under study in a wider context involving 27 cases. Results indicate that only an environment-led policy is capable of reducing the intensity of the conflict. The other two proposed development tracks focussing on economic efficiency and social equity would slightly aggravate the conflict.
The High Water Mark (HWM) is an important cadastral boundary that separates land and water. It is also used as a baseline to facilitate coastal hazard management from which land and infrastructure development is offset to ensure the protection of property from storm surge and sea level rise. The determination of the HWM has a long history. Its definition, the mean and even the corresponding determination methods have changed through time. In addition, the location of the HWM is difficult to define accurately due to the ambulatory nature of water and coastal morphology variations.
To better understand the HWM determination, this paper reviews the development of the definition of HWM, including ordinary high water mark (OHWM), mean high water mark (MHWM), mean high water spring (MHWS) and mean higher high water (MHHW), and the existing HWM indicators, such as vegetation line and beach morphological features. Two common methods of HWM determination, field survey and remote sensing, are discussed in this paper. This is followed by the investigation of the possible factors that influence the variation of the HWM position. Furthermore, an overview of the ambulatory nature of both water and coastal morphology, which contributes to the difficulties in HWM determination, is provided. Finally, the limitations of previous determination methods and future direction in HWM determination studies are also discussed. This study concludes that it is necessary to develop a robust analytical system to identify, evaluate and integrate various factors into the process of determining the HWM.