High Seas Areas Research Articles

China-U.S. cooperation in the Arctic Ocean: Prospects for a new Arctic exceptionalism?

There are currently many sources of tension between the People’s Republic of China and the United States of America. In the Arctic, the relationship includes competition for influence as well as cooperation in governance, such as the Central Arctic Ocean (CAO) Fisheries Agreement. The prospect of further cooperation creates an opportunity for a new “Arctic exceptionalism,” in which China and the U.S. could move towards better mutual understanding. Doing so would benefit the Arctic and could help improve bilateral relations more generally. For example, China and the U.S. can work with other countries to improve research and governance of the Arctic Ocean. Regional governance agreements for commercial shipping and deep-sea mining in high-seas areas of the Arctic could build on the principles of the CAO Fisheries Agreement while building trust and shared commitment to a healthy Arctic Ocean, perhaps setting the stage for more ambitious collaborative efforts.

Designating Particularly Sensitive Sea Areas in Areas Beyond National Jurisdiction

While the International Maritime Organization’s (IMO) Particularly Sensitive Sea Area (PSSA) concept has been operational for over 30 years, no state has ever brought forward a proposal for a high seas PSSA. This is despite the fact that shipping demonstrably poses a threat to high seas biodiversity. The adoption, by the United Nations, of a new implementing agreement for the conservation and sustainable use of biodiversity in areas beyond national jurisdiction (BBNJ Agreement) opens a new chapter in the governance of the high seas, and creates, for the first time, a legal mechanism, agreed at the global level, for the establishment of area-based management tools (ABMTs). This new agreement strengthens the arguments for utilizing the PSSA regime in the high seas and, as a consequence, has implications for the IMO, and how its member states consider the potential application of PSSAs in areas beyond national jurisdiction (ABNJ). Drawing on recent discussions concerning the potential to designate two specific high seas areas as PSSAs, namely, the Sargasso Sea and the Costa Rica Thermal Dome, this article examines the practical issues to be addressed when applying the PSSA concept to the high seas and considers the opportunities for advancing PSSA proposals through enhanced cooperation between the IMO and the parties to the BBNJ Agreement.

Design and Optimization of PV Power Supply System for Marine Buoys

Marine buoys need to operate in high sea areas far from land for a long time. Therefore, how to provide a long-term power supply for the buoy system is critical to be addressed. Photovoltaic (PV) power supply systems are the most commonly used power supply method for marine buoys. Due to the limitations of the buoy structure and considering the rotation of the buoy in the ocean, most of the PV modules are placed in a four-sided enclosure. The output performance of the PV power supply system in this placement is affected by the tilt angle produced by waves. However, there are few relevant studies on the actual power generation performance of PV power supply systems for marine buoys, and there is a lack of methods for power generation performance analysis. In order to meet the power requirements of the marine buoy, a large design margin must be left. It increases the cost of marine buoys. In this paper, second-order Stokes waves are used to simulate waves of different levels by varying the wave height and frequency. The motion characteristics of the marine buoy are analyzed using ANSYS-AQWA under calm-rippled, smooth, slight, and moderate conditions. Combined with the tilted surface irradiance calculation model to get the variation law of solar radiation of PV modules under dynamic conditions, the effect of different tilt angle PV modules on the output of PV system under dynamic conditions was also studied. The experiments show that for every 5° increase in the tilt angle of the PV modules the output power of the system decreases by 3% on average. As the tilt angle of the PV modules increases, the impact on the system output performance is more pronounced. The output power decreased by 69.5% when the PV modules were tilted at an angle of 90°, and the PV system electrical parameters were similarly affected. By comparing the influence of different tilt angles on the power supply performance of PV modules, we optimize the design of the PV power supply system of the buoy. This enables the designers to maximize the use of limited area and space while reducing the cost and extending the power supply time and service life of the buoy.

An Analysis of Policy Options Available to the International Maritime Organization to Protect the Costa Rica Thermal Dome: Building the Case for a Particularly Sensitive Sea Area

Intense maritime traffic threatens marine habitats globally. The Costa Rica Thermal Dome (CRTD) is a biologically productive ocean region that experiences a high volume of maritime traffic, and its location is dynamic, representing a governance challenge for this marine area. The CRTD is a high seas upwelling system influenced part of the year by coastal jet winds off the coast of Nicaragua and Costa Rica. During parts of the year, the CRTD moves into the jurisdictional waters of the adjacent countries (Costa Rica, Nicaragua, Guatemala, and El Salvador). Because there is currently no cross-sectoral coordination or capacity to address multiple threats in high seas areas such as the CRTD, regulation must be implemented on a sector-by-sector basis. This document analyzes tools under the International Maritime Organization (IMO) to reduce the threats from international shipping in the marine environment, with particular emphasis on the CRTD. The IMO has the authority to regulate shipping activity globally and implement precautionary measures to avoid threats such as hazardous and noxious substances, ship-whale strikes, or underwater noise pollution. The following IMO tools were included in the analysis: ship routing measures and speed reductions, a Special Area under the International Convention for the Prevention of Pollution from Ships (MARPOL), and a Particularly Sensitive Sea Area (PSSA). The results of the analysis concluded that the implementation of a PSSA within the CRTD is the best option to address threats from international shipping, since it can combine a range of Associated Protective Measures under its single administrative structure.

Enhancing cooperative responses by regional fisheries management organisations to climate-driven redistribution of tropical Pacific tuna stocks

Climate change is predicted to alter the distributions of tropical tuna stocks in the Pacific Ocean. Recent modelling projects significant future shifts in tuna biomass from west to east, and from national jurisdictions to high seas areas. As the distributions of these stocks change, the relevant regional fisheries management organisations (RFMOs)—the Western and Central Pacific Fisheries Commission (WCPFC) and the Inter-American Tropical Tuna Commission (IATTC)—will need to develop an expanded framework for cooperation and collaboration to fulfil their conservation and management responsibilities under international law. The key elements of a possible expanded framework for cooperation can be developed, and fundamental areas for collaboration identified, by applying and adapting principles established in the United Nations Convention on the Law of the Sea, the United Nations Fish Stocks Agreement, and the constituent instruments of the RFMOs themselves. Our analysis reveals a wide range of important issues requiring cooperation, and three clear priorities. First, a formal mechanism for cooperation is needed to enable effective and efficient decision-making and action by the two RFMOs on key issues. Second, further cooperation is required in scientific research and modelling to better understand the biology and distributions of Pacific tuna stocks and how they will respond to climate change, and to inform stock assessments and harvest strategies. Third, the RFMOs must cooperate to define appropriate limits on fishing for each stock in a way that ensures they are compatible across the two organisations, taking into account their different members and management regimes.

Regional-scale genetic differentiation of the stony coral Desmophyllum dianthus in the southwest Pacific Ocean is consistent with regional-scale physico-chemical oceanography

Deep-sea corals are diverse and abundant in New Zealand’s EEZ and the southwest Pacific Ocean. We assessed genetic diversity and gene flow of the deep-sea scleractinian (stony cup coral) Desmophyllum dianthus in five areas (Kermadec Ridge, Louisville Seamount Chain, Chatham Rise, Campbell Plateau, Macquarie Ridge), and applied dispersal kernels estimated from drifters observations and seascape genetics to compare with observed connectivity patterns and regional physico-chemical data. We observed pronounced between-region genetic differentiation, high levels of self-recruitment, but also high connectivity between distant sites (e.g., at the Kermadec Ridge inside the New Zealand EEZ, and the Louisville Seamount Chain outside the New Zealand EEZ). Genetic diversity was marginally highest at the Kermadec Ridge, whilst populations on the Chatham Rise showed evidence of unique genetic diversity that may be driven by converging ocean currents. Overall, patterns of genetic connectivity were consistent with oceanographic predictions of dispersal routes. Seascape genetic analyses indicated that environmental variables most often related to physical seafloor habitat characteristics were important predictors of regional-scale genetic differentiation of D. dianthus. Our research shows that current spatial closures within the New Zealand EEZ and surrounding high seas areas do not encompass the extent of genetic diversity and connectivity for D. dianthus, which parallels research for other deep-sea taxa in the region. Future measures implemented to protect deep-sea coral biodiversity require consideration of complex connectivity patterns and migration routes amongst taxa, at various spatial scales. This study demonstrates that a combined gene flow, seascape genetics and dispersal kernel modelling approach can provide a robust evaluation of connectivity in deep-sea environments to inform management decision making at the scale of the southwest Pacific Ocean.

A Multi-Region and Multi-Period Harvest Schedule of the Trawl Fleet

Under the individual vessel quota regulations, the expected economic return of a multi species fishery is influenced by an array of a multi-component choice such as targeted species, landings per haul, harvesting time and its location. The components of effort allocation decisions are further complicated by changes in the market conditions and the constant movements of fish between spawning and feeding habitats. Migratory behavior influences the dispersal of species, relative availability of fish and its composition, and the bycatch likelihood across different locations over the course of a fishing year. The objective of this article is to investigate the optimal allocation of fishing effort in the Norwegian bottom-trawl fleet within economically important species; cod, saithe, and haddock across three heavily trawled areas—including southern and northern parts of the west coast of Norway, and the high sea areas of the Arctic—to achieve maximum expected economic return, with respect to the individual vessel quota constraints and bycatch considerations. The results from a mixed integer non-linear optimization problem evidence that the spawning migration of Northeast Arctic cod along the northwest coast, effort allocation behavior of coastal fleet, together with institutional regulations necessitate the substitution of fishing effort across different fishing locations within the fishing season to maximize expected return. The results of our study further reveal that the Arctic region to target cod is the biggest contributor to annual fishing revenue. By contrast, conducting saithe fishery in the southwest of the Norwegian coast has the lowest economic contribution. The results from Monte Carlo simulation demonstrate that the proposed model is effective and applicable for effort allocation decision analysis.

Combined Abundance of All Vulnerable Marine Ecosystem Indicator Taxa Inadequate as Sole Determiner of Vulnerability, Antarctic Peninsula

In order to achieve conservation objectives and preserve the biodiversity of the Southern Ocean, a variety of ecosystems must be protected. This holds especially true for the benthic communities of this region that are characteristically mosaic in their spatial distributions. As such, disparate communities cannot be comprehensively assessed by a single blanket methodology. Herein, evidence appropriate to the diverse characteristics of the communities encountered during a submarine expedition demonstrates the particular vulnerability of four sites that exemplify VMEs as defined by the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) and the UN’s Fisheries and Agriculture Organization (FAO). Three sites are identified as VMEs based on highly significant abundances of indicator taxa. A fourth is identified based on a high density of cold-water coral taxa, many of which were not observed in abundance at the sites that were triggered as vulnerable by a significantly high abundance of all indicator taxa. The VME at this latter site was richly diverse in coral taxa, many of which are considered particularly vulnerable to climate change, as well as critical for their potential for genuine blue carbon sequestration. As of November, 2018, all four sites are now registered with CCAMLR as VMEs and thus, are afforded protection from all bottom fishing activities. However, if consideration isn’t given to the composition and/or diversity of VME indicator taxa present, in addition to overall abundance/density, some of the most vulnerable communities are left at risk. A blanket threshold for all VME taxa adhered to in fisheries management of the Southern Ocean, and other high seas areas, is grossly insufficient. Without taking a more precautionary approach to identifying and protecting VMEs, CCAMLR will not be able to meet its conservation objectives and may even be putting Antarctic fisheries at risk.

Intra- and inter-temporal effort allocation and profit-maximizing strategy of trawl fishery

AbstractBottom trawlers are engaged in multi-species fisheries and fish for profit. In quota-regulated fisheries, intra- and inter-temporal substitutions of fishing effort is regarded as a key mechanisms that influences the profitability of the fishing portfolio. The feeding and spawning migration patterns of the available fish species in the fishing portfolio alter the bio-economic conditions of the different fishing areas. In addition, the spatial heterogeneity among different fishing areas in terms of the fuel costs and travel distance, accessibility to other fishing fleets, and sea ice extent affects the relative attractiveness of the fishing areas and further complicates the decisions underlying the effort allocation, such as when and where to fish what and how much to fish to maximize the profit. In this regard, the aim of this article is to identify the key drivers of intra- and inter-temporal effort allocation in a multi-species trawl fishery consisting of 61 Norwegian trawl vessels targeting cod, saithe, and haddock, the aim being to maximize the fishing profit within the quota constraints. We adopted a two-step Heckman estimator that incorporates the relative attractiveness of three heavily trawled areas, the southern and northern parts of the west coast of Norway and the high sea areas of the Arctic. The relative attractiveness is specified by the fish availability, measured using the catch per unit of effort, prices of the target species, fuel cost, intensity of the coastal fleet's participation in winter fishery, and seasonal sea ice extent in the Barents Sea during the period 2011–2016. Our results show that region-specific attributes and spatial margins have a profound impact on the intra-temporal and inter-temporal allocation of fishing effort to maximize the seasonal profit. Furthermore, we found evidence of economically rational behaviour of the Norwegian trawlers in constantly reallocating their fishing effort in response to the changes in the relative attractiveness of the selected fishing areas over the course of a fishing year.

Mapping interests in the tuna fisheries of the Western and Central Pacific Ocean

Fisheries for highly migratory fish stocks are complex, featuring multiple species targeted by different gear types across several national jurisdictions and high seas areas. They require effective cooperation to manage sustainably, typically through a regional fisheries management organisation (RFMO). However, diverse interests in different species and gear types among participating states and fishing entities, many of which are developing, mean that cooperation can be difficult to achieve, with severe consequences for fish stocks, the economies of states with an interest in those stocks, and the livelihoods of communities that depend on them. The Western and Central Pacific Fisheries Commission (WCPFC) manages some of the world's largest tuna fisheries and exemplifies these challenges. We argue that a prerequisite for effective cooperation is an understanding of the interests of each participant in each species and gear type to ensure that conservation and management measures take into account the differential impacts on each one, including whether measures place a disproportionate burden on developing states. This paper uses catch value data for four key tuna species of the WCPFC convention area to illustrate the diversity of interests of participants in these fisheries, with a view to enhancing delegations' understanding of those interests and to inform more effective cooperation.

Valuing high‐seas ecosystem conservation

The high seas are known to provide a variety of ecosystem services that are of benefit to society. There have however been few attempts to quantify the welfare impacts of changes to the delivery of these benefits. This study assesses the values of several key ecosystem service benefits derived from protecting ecosystems in the high seas area of Flemish Cap. To accomplish this analysis a choice experiment was conducted in three countries: Canada, Norway and Scotland. Rather than solely eliciting public willingness-to-pay, we went a step further to explore the determinants of variance in these estimates. Specifically, we aimed to answer three research questions: (1) how much are respondents willing to pay for high-seas ecosystems conservation, (2) which factors influence individual willingness-to-pay, and (3) whether individuals residing in Canada have a higher willingness-to-pay compared to those living in Norway and Scotland. This latter question captures distance-decay effects. The results show that on average the public placed positive value on conserving high-seas ecosystems and on developing economic activities related to the exploitation and exploration of marine resources, despite a lack of awareness and familiarity with these environments. Distance-decay effects on willingness-to-pay were not clear, as the Scots had the highest willingness-to-pay and the Norwegians the lowest willingness-to-pay for all attributes, with the only exception being willingness-to-pay for a large increase in new jobs where Canadian willingness-to-pay was higher than for the Scots. The public willingness-to-pay was influenced by socio-demographic characteristics and their perceptions of high-seas ecosystems. Our study provides the evidences of the impacts of high-seas governance on the welfare of people, and the improved governance could increase the values of high-seas ecosystems and the services they produce. Article impact statement: The public is willing to pay for the conservation of remote environments that they have little direct use for or experience with. This article is protected by copyright. All rights reserved.

Research Gap Analysis of Remote Sensing Application in Fisheries: Prospects for Achieving the Sustainable Development Goals

Remote sensing (RS) technology, which can facilitate the sustainable management and development of fisheries, is easily accessible and exhibits high performance. It only requires the collection of sufficient information, establishment of databases and input of human and capital resources for analysis. However, many countries are unable to effectively ensure the sustainable development of marine fisheries due to technological limitations. The main challenge is the gap in the conditions for sustainable development between developed and developing countries. Therefore, this study applied the Web of Science database and geographic information systems to analyze the gaps in fisheries science in various countries over the past 10 years. Most studies have been conducted in the offshore marine areas of the northeastern United States of America. In addition, all research hotspots were located in the Northern Hemisphere, indicating a lack of relevant studies from the Southern Hemisphere. This study also found that research hotspots of satellite RS applications in fisheries were mainly conducted in (1) the northeastern sea area in the United States, (2) the high seas area of the North Atlantic Ocean, (3) the surrounding sea areas of France, Spain and Portugal, (4) the surrounding areas of the Indian Ocean and (5) the East China Sea, Yellow Sea and Bohai Bay sea areas to the north of Taiwan. A comparison of publications examining the three major oceans indicated that the Atlantic Ocean was the most extensively studied in terms of RS applications in fisheries, followed by the Indian Ocean, while the Pacific Ocean was less studied than the aforementioned two regions. In addition, all research hotspots were located in the Northern Hemisphere, indicating a lack of relevant studies from the Southern Hemisphere. The Atlantic Ocean and the Indian Ocean have been the subjects of many local in-depth studies; in the Pacific Ocean, the coastal areas have been abundantly investigated, while offshore local areas have only been sporadically addressed. Collaboration and partnership constitute an efficient approach for transferring skills and technology across countries. For the achievement of the sustainable development goals (SDGs) by 2030, research networks can be expanded to mitigate the research gaps and improve the sustainability of marine fisheries resources.

The shared fish stocks conservation: revisiting the unconnected enforcement

“There is plenty of other fish in the sea," goes the old cliché as many stocks have been overfished by industrial fisheries, that the over-activity made some fish species in danger. The scope of this paper covers the enforcement issue of Southern Bluefin Tuna (SBT) as endangered fish species. Taking Indonesia, New Zealand, and Australia as member States who catch SBT, this paper is a conceptual study using content analysis aiming to review how these three-member States officially treat SBT stocks. Based on the discussion, it found that since the shared characteristic of SBT, in areas beyond national jurisdiction it might create regulatory gaps. While international provisions have been entered into force in respect of endangered fish stocks in high seas areas, however, a lacuna remained in which the law cannot reach the national fishing area. This situation may lead to a discrepancy framework at the national level. Therefore, this paper argues that connectivity is crucial to link enforcement among relevant States with the real interest. In this context, the enforcement must consider the movement path of SBT from a coastal State (the spawning ground), the flag State (the fishing vessel), and the Port State (the place to land SBT).

Compliance Evaluation and Sustainable Resource Management in the CCAMLR

Regional fisheries organisations globally are feeling the impacts of non-compliant behaviour by both contracting and non-contracting parties. Non-compliance arising from activities such as illegal, unreported and unregulated fishing, or failures by flag states to appropriately report the activities of their vessels, has resulted in damage to the environment and damage to the performance of regional fisheries management organisations themselves. As a result, many of these organisations are adopting and implementing a relatively new mechanism to tackle non-compliance: the compliance evaluation procedure. This article demonstrates that by adopting a compliance evaluation procedure, regional fisheries organisations are better placed to identify and address non-compliance in an effort to improve compliance with their conservation measures. It analyses in detail the procedure adopted by one particular organisation, the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR), to suggest that implementation of their procedure has improved transparency, accountability and enforcement. It is argued that the CCAMLR compliance evaluation procedure represents a model for other polar and high seas areas to promote sustainable, and responsible, fishing practices globally.

Development of Innovative Solutions for Intelligent Inspection of Products of Additive Manufacturing for Navy Supply

Using of 3D printed spare parts for Navy supply supported by mentioned inspection meets the requirement for enhancing the logistic performance by provide to military end-users possibilities to produce spare parts using additive manufacturing solutions, particularly in the context of overseas operations, that can be easily presented with several examples. But with application of additive manufacturing in naval operations to product different objects in a variety of materials in an open water environment, we need to start with development of innovative solutions for intelligent inspection of products of selective laser melting from metallic powders is a topic of great importance in nowadays if we talk about real strategies in logistic support including overseas naval outposts support equipment and the reverse engineering of obsolescent parts such as many of those that could be found on the perspective sea platforms with particular focus on maritime littoral and high sea areas—demonstrate advantages of additive manufacturing.

Spatial and temporal distributions in the Norwegian cod fishery

AbstractFisheries are characterized by variations in space and time. This study investigates the characteristics of seasonality in cod trawl fisheries in two distinct areas: the coast along the northern Norway and the high sea area of the Barents Sea. Catch per unit effort (CPUE) is used to proxy variation in stock abundance. A CPUE function has been estimated in the frequency‐domain framework, to detect the presence of seasonality. Our analysis reveals that seasonality in stock abundance is only present in the northern coast of Norway. We conclude that as a consequence of seasonality in stock aggregation during the first quarter of the fishing year, possible economic losses caused by reduced prices—stemming from a large supply of cod—are larger than the economic benefits from cost reduction per unit of harvest. We speculate that declined price and consequently potential economic losses encourage trawlers to substitute cod by other high‐value fisheries during the winter months. As the price of cod starts to rise after the first quarter, trawlers begin to target cod in the high sea areas, a region with less seasonality.

Turtles on the trash track: loggerhead turtles exposed to floating plastic in the Mediterranean Sea

ESR Endangered Species Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials ESR 40:107-121 (2019) - DOI: https://doi.org/10.3354/esr00980 ESR Special: Marine pollution and endangered species Turtles on the trash track: loggerhead turtles exposed to floating plastic in the Mediterranean Sea A. Arcangeli1,*, F. Maffucci2, F. Atzori3,4, M. Azzolin5, I. Campana6, L. Carosso6, R. Crosti1, F. Frau3, L. David7, N. Di-Méglio7, M. Roul7, M. Gregorietti8, V. Mazzucato6, G. Pellegrino6, A. Giacoletti9, M. Paraboschi6, A. Zampollo5, G. A. de Lucia10, S. Hochscheid11 1ISPRA, Department for Biodiversity Conservation and Monitoring, Via Brancati 48, 00143 Rome, Italy 2RIMAR Department, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy 3Capo Carbonara MPA- Municipality of Villasimius, 09049 Villasimius (SU), Italy 4Department of Ecological and Biological Sciences, Ichthyogenic Experimental Marine Center (CISMAR), Tuscia University, Borgo Le Saline, 01016 Tarquinia, VT, Italy 5Gaia Research Institute, Corso Moncalieri 68B, 10133 Torino, Italy 6Accademia del Leviatano, Via dell'Ospedaletto 53/55, 00054 Maccarese, RM, Italy 7EcoOcéan Institut, 34090 Montpellier, France 8BioacousticsLab, CNR-IAS, Institute of Anthropic Impact and Sustainability in Marine Environment - National Research Council, Via del Mare 3, 91021 Torretta Granitola (TP), Italy 9Department of Earth and Marine Science (DiSTeM), Laboratory of Ecology, University of Palermo, Viale delle Scienze Ed. 16, 90128 Palermo, Italy 10CNR-IAMC, Institute for Coastal Marine Environment - National Research Council, Torregrande (OR), Italy 11Marine Turtle Research Center, Stazione Zoologica Anton Dohrn, Via Nuova Macello 16, 80055 Portici, Italy *Corresponding author: antonella.arcangeli@isprambiente.it ABSTRACT: Loggerhead turtles Caretta caretta spend most of their life in large marine areas occupying a variety of habitats where they are exposed to different types of threats. Among these, marine litter poses a risk of entanglement or ingestion. Areas of risk exposure can be identified where the species overlap with litter accumulations, but gathering data on this highly mobile species and marine litter, especially in high sea areas, is challenging. Here we analysed 5 years of sea turtle and marine litter data collected by a network of research bodies along fixed trans-border transects in the Mediterranean Sea. Ferries were used as observation platforms to gather systematic data on a seasonal basis using standard protocols. Loggerhead turtle sightings over time and space were compared in terms of sightings per unit effort, and risk-exposure areas were assessed based on seasonal overlap of species hot spots and high-density plastic areas revealed by kernel analysis. In almost 180000 km surveyed, 1258 sea turtles were recorded, concentrated mostly in the central Adriatic Sea and Sardinia-Sicilian channels during all seasons, and in the central Tyrrhenian Sea during spring. Plastic comprised the highest fraction of litter items detected. Several areas of higher risk exposure, both permanent and seasonal, were identified, mainly in the Adriatic Sea and during the spring-summer seasons. Records of both species and floating litter were highly variable, underlying the need for continuous long-term monitoring to develop sound conservation and management measures, especially in the identified areas of risk exposure. KEY WORDS: Loggerhead turtle · Caretta caretta · Marine litter · Mediterranean Sea · Monitoring · Risk assessment Full text in pdf format PreviousNextCite this article as: Arcangeli A, Maffucci F, Atzori F, Azzolin M and others (2019) Turtles on the trash track: loggerhead turtles exposed to floating plastic in the Mediterranean Sea. Endang Species Res 40:107-121. https://doi.org/10.3354/esr00980 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in ESR Vol. 40. Online publication date: October 30, 2019 Print ISSN: 1863-5407; Online ISSN: 1613-4796 Copyright © 2019 Inter-Research.

Dimensions of transboundary legal coherence needed to foster ecosystem-based governance in the Arctic

The Arctic is a complex geographical area to govern sustainably due to strong geopolitical and socio-economic interests, high ecological vulnerability and importance, and significant legal and institutional fragmentation. Intensifying human pressures in this area necessitate an ecosystem-based and adaptive governance approach, an approach that enables managing socio-ecological resilience in the Arctic. As the Arctic is a large geographic area crossing multiple national jurisdictions and maritime zones, including high seas areas, regionally coordinated and coherent governance approaches would be desirable. This paper assesses the status quo for ecosystem-based governance (EBG) in the Arctic, suggests a focus on three core components of EBG, and proposes three forms of legal coherence to foster these core components. The paper concludes with examining what role the Arctic Council plays and could play to strengthen EBG in the Arctic.

Spatiotemporal dynamics of the Pacific chub mackerel revealed by standardized abundance indices

Standardization of catch per unit effort is an effective way to not only extract temporal abundance trends but also understand distribution shifts of fish resources. Chub mackerel in the Northwest Pacific has recently been of great concern to fishermen and fisheries managers because the total catch has been increasing, and fishing grounds have expanded from the Japanese exclusive economic zone eastward to high-sea areas. Understanding the spatiotemporal dynamics of chub mackerel is urgently needed for evaluating the current status (i.e., abundance and distribution) and considering future exploitation. Here we constructed two recruitment indices from pelagic trawl survey data of the Pacific chub mackerel. For recruitment indices of age-0 fish, we integrated an algorithm for automatic area stratification into the delta-GLM that combines two separate generalized linear models (for encounter probability and positive catch rates) to simultaneously investigate changes in relative abundance and distribution. Recruitment indices were high in the recent years of 2013, 2016, and 2017, especially at around 160 °E longitude within the high-sea areas, suggesting simultaneous changes in abundance and distribution. Furthermore, we found that our approach had better predictive ability, especially for positive catch rates, than that of a generalized additive model by cross validation, and the obtained standardized indices mitigated potential bias in stock assessment estimates. Our integrated approach will be useful for understanding the spatiotemporal dynamics of fishes and standardizing abundance indices for stock assessment and management.

Regional connectivity and spatial densities of drifting fish aggregating devices, simulated from fishing events in the Western and Central Pacific Ocean

The increased use of drifting Fish Aggregating Devices (dFADs) by tuna purse seine fleets in recent years has supported considerable catches of these species. A greater understanding of the spatiotemporal dynamics of these objects as they drift with ocean currents is critical for understanding historical changes in fishing power, spatial management, and examining the effect of ambient dFAD density on catch and effort. Here, dFAD dynamics were estimated for all floating object sets made by purse seiners in the Western and Central Pacific Ocean during 2016 and 2017. The drift trajectories of these floating objects prior to the observed fishing events were estimated by seeding virtual Lagrangian particles within a state-of-the-art hydrodynamics model, and simulating their movements backwards in time. Resulting trajectory distributions are similar to observed dFAD trajectories from the same period. The approach provides spatial density estimates in areas where observed dFAD data are incomplete, particularly in the exclusive economic zone (EEZ) of Howland and Baker Islands, and certain high seas areas. We provide estimates of inter-EEZ connectivity of dFADs, which highlight the fact that dFADs set upon in small EEZs such as Nauru and Howland and Baker Islands are likely to have drifted from neighbouring EEZs less than one month prior to fishing. dFADs typically transited multiple EEZs, with a median of 4 and a maximum of 14, when assuming a drift-time of six months. Moreover, between 4 and 22% of dFAD sets made in the WCPO were estimated to have originated from the Eastern Pacific Ocean, depending on drift-time. We examine our results in the context of the improved management and assessment of dFAD fisheries, providing a methodology to estimated relative dFAD density over historical periods to support analyses of catch and effort. The sensitivity of these estimates to hydrodynamic models, including the proposed SKIM doppler radar altimetry method, is discussed.