Exploratory Fishing Research Articles

The Central Arctic Ocean Fisheries Agreement and Arctic Indigenous peoples

The Agreement to Prevent Unregulated High Seas Fisheries in the Central Arctic Ocean (CAOFA) is a unique treaty that deals with a unique scenario: in an area of the high seas where no fishing has ever taken place, it determines the conditions under which future fishing can commence. Another innovation for which the CAOFA is less well-known are various aspects relating to Arctic Indigenous peoples. This article examines Arctic Indigenous issues relating to the CAOFA and focuses in particular on the participation of Arctic Indigenous peoples in the negotiations on the CAOFA and subsequent meetings of the CAOFA, as well as the needs of, and impacts on, Arctic Indigenous peoples as considerations in decisions by the CAOFA’s Conference of the Parties (COP) on commercial and exploratory fishing.

Mesopelagic Mysteries: Regulating an Emerging Resource Amid Uncertainty

Mesopelagic species, which inhabit depths between 200 to 1000 m, have regained attention as potential new resources to replace and supplement the use of traditionally overfished species. Research and exploratory fishing are ongoing, yet much on the nature of mesopelagic organisms and their roles within ecosystems and the carbon cycle remains to be understood. Building on recent reports and reflecting on fisheries developments, this article examines some of the unique characteristics of the mesopelagic zone and the existing international legal framework to stimulate legal debate on the sustainable management of mesopelagic fish stocks in the high seas.

Reef Fish in the Vitória-Trindade Seamount Chain of the Southwestern Atlantic: Biogeographical Corridors and Impact of Fishing

This paper aimed to study the community structure of large reef fish off the central coast of Brazil by defining the spatial distribution patterns of 34 species in the outer shelf (50 to 100 m) between 13 and 22ºS, including sea banks, seamounts and the Trindade Island, seeking further to interpret these patterns in light of biogeographic knowledge. In addition, this study attempted to estimate the impact of fishing on the community in different regions using mean weight and size distribution data. The data were obtained in four exploratory fishing surveys of demersal resources employing a bottom longline with steel wire under the aegis of the REVIZEE Program between 1996 and 1998. The numerical abundances were standardised in catch-per-unit-effort (CPUE) in number, and species matrices per station were subjected to detrended correspondence analysis (DCA) and cluster analysis. Reef fauna in the southwestern Atlantic can be divided, in its continental margin, into a tropical component and a subtropical component from latitude 19ºS, which corresponds to the Southern limit of the Abrolhos Bank. North of 19ºS, four distribution patterns were identified (North, Abrolhos, Banks and Trindade). The similarity between the last three enabled the definition of an “Abrolhos-Trindade faunal complex”. Evidence of the impact of commercial fishing on the structure of reef communities was found through differences in the sizes of species studied, which may have occurred differently in each one of the regions of the Abrolhos-Trindade complex. The results also reinforce the importance of the need for conservation measures in these areas.

Stochastic Multi-species MSY to Achieve Ecological-Economic Sustainability of a Coral Reef Fishery System in French Polynesia

This paper investigates the ecological-economic sustainability of coral reef socio-ecological systems under fishing and environmental pressures. To achieve this, a dynamic, spatially explicit, multi-species, multi-fleet fisheries model is developed. Stochastic environmental shocks are assumed to alter coral cover and consequently the entire coral reef social-ecological system. The model is calibrated using ecological, socio-economic and environmental data in French Polynesia. Four exploratory fishing strategies and a goal-seeking strategy entitled Stochastic Multi-Species Maximum Sustainable Yield (SMMSY) are compared in terms of ecological-economic outcomes and sustainability of the socio-ecological system. The SMMSY turns out to promote ecological-economic sustainability. It is characterised by a global increase in fishing effort pointing to the relative current under-exploitation of the fishery. SMMSY balances the trophic level of catches after natural shocks and sustains the fundamental herbivore grazing process. SMMSY strategies are also more diversified in terms of temporality, gears, spatial distribution of fishing and target species.

Regulating Exceptions for Research and Exploratory Fishing in Southern Ocean Marine Protected Areas: A Comparative Analysis on Balancing Conservation and Commercial Use

This article examines the concepts of “research fishing” and “directed fishing” under the Ross Sea region Marine Protected Area (RSrMPA) with specific regard to MPAs as a conservation tool, drawing comparisons with related concepts contained in two other agreements, namely, the 1946 International Convention for the Regulation of Whaling (ICRW) and the 2018 Agreement to Prevent Unregulated High Seas Fisheries in the Central Arctic Ocean (CAOF Agreement). It first reviews the negotiation processes of the RSrMPA, focusing on debates between so called “fishing states” and “conservation states,” as well as the political compromise that led to the establishment of the RSrMPA. Second, it takes a detailed look at the regulation of “research fishing” and “directed fishing,” which may be conducted in the RSrMPA and the three zones into which it is divided. Third, it analyzes how “scientific research activities” and “exploratory fishing” are regulated in the CAOF Agreement. Thereafter, this article examines the role of the concept of whaling “for purposes of scientific research” under the ICRW. It concludes with an assessment of differences and similarities between the analyzed regulatory instruments, which identifies recommended lessons for the design of Conservation and Management Measures establishing MPAs that both reflect the precautionary approach and strike a balance between conservation and utilization.

Influence of anticyclonic, warm-core eddies on mesopelagic fish assemblages in the Northwest Atlantic Ocean

Variability in mesopelagic fish assemblages of the deep-scattering layer were explored in relation to mesoscale anticyclonic (warm-core) eddies in the western North Atlantic Ocean. Exploratory fishing with a mid-water herring trawl was combined with oceanographic sampling aboard the RV Celtic Explorer in the Spring of 2015 and 2016 to characterize mesopelagic fish assemblages along transects through anticyclonic eddies identified using real time satellite-derived sea level anomaly. Sampling yielded a total of 6087 fish specimens, representing at least 109 species across 38 families. The families Myctophidae and Stomiidae were the most speciose taxa sampled and comprised >50% of total catch abundance in each year. Species richness and diversity (H’) were significantly higher in sets occurring inside relative to outside the eddy structures. Community analyses indicate significant differences in daytime assemblage structure between both depth groups (shallow 200–400 m versus deep 400–700 m) and eddy groups (inside versus outside), with ordination discrimination of 5 pelagic fish assemblages related to eddy groups. Anticyclonic eddies also harbored more juveniles and rare species, including species with more southerly distributions within the Gulf Stream. Our results indicate anticyclonic eddies may play an important role in structuring fish assemblages and the dispersion of mesopelagic species in the Northwest Atlantic.

Behaviourally-mediated learning ability in an invasive marine fish

Invasive species can have profound impacts in non-native environments, the mechanisms behind which are often unclear. Learning and memory are notably two traits that may facilitate their impact. Behavioural traits can subsequently mediate learning ability in invasive species, the interaction between which may provide means by which to both better understand and manage invaders. We evaluated this relationship in lionfish (Pterois volitans), a species introduced to and invasive in the western Atlantic Ocean. We trained lionfish in a food reward task and assessed the degree to which behavioural traits and navigation strategy influenced their performance. We then evaluated memory retention by subjecting fish to training breaks of 5 to 42 days. Lionfish exhibited high inter-individual variability in learning. Half of the lionfish tested learned to navigate the maze, whose performance was strongly mediated by behaviour. Learning ability was positively correlated with boldness, exploratory tendency, and speed of task completion, but irrespective of spatial navigation strategy. However, fast exploratory fish trained in the complex navigation strategy had difficulty adapting to changing environmental conditions, indicative of a speed-accuracy trade-off. Lionfish were able to remember the location of the food reward for up to 6 weeks. Behavioural-mediated learning may help explain and understand the high impact of lionfish and other non-indigenous species in their invaded range and may elucidate spatiotemporal context-dependencies in their ecological impact.

Estimation of Post-Harvest Losses of Fish Transported Using Ice-chilled Carrier Boats from High Seas Pocket 1

Access of Philippine traditional fresh/ice-chilled seining vessels to High Seas Pocket 1 (HSP-1) lessens fishing pressures in the Philippine Exclusive Economic Zone where juvenile oceanic tunas are more likely to be found. However, catch landed by carrier boats from HSP-1 were observed to be of reduced quality, thus eliciting lower market value. The present study was conducted to evaluate the efficiency of icechilled carrier boats by generating data on the magnitude of post-harvest losses incurred in landed catch from HSP-1. Exploratory Fish Loss Assessment Method and Questionnaire Loss Assessment Method were used to estimate quality losses. Landed catch of ice-chilled carrier boats from HSP-1 recorded an estimated loss of 17.25%. Key players incurred an estimated financial loss amounting to PHP 223 million (USD 4.3 million). Low quality catch commonly sold as raw materials for canning, smoking, and fishmeal processing entail cheaper prices, thus regarded as losses. A positive correlation was established between fishing duration and losses. Results indicate that the current preservation technique in carrier boats could induce quality deterioration in fish given the long distances and transit times involved. Thus, the use of carrier boats with freezing system should be allowed in HSP-1 to sufficiently preserve the quality of the catch. This will reduce losses in post-harvest fisheries, thereby increasing the potential income of HSP-1 players.

<strong>New reports of echinoderms on the Caribbean continental slope of central America</strong>

The Caribbean is considered a unique biogeographic region that represents an important hotspot of marine diversity in the Atlantic Ocean. The Caribbean Continental Slope of Central America (CCCA) is a largely unexplored area that exhibits a variety of habitats. Among this unstudied biodiversity, special importance has been given to the benthic communities associated with deep bottoms, a diverse group that plays a major role in the ocean carbon cycling and nutrient flux. Echinoderms are one of the main benthic deep sea taxa, in which Holothuroidea is the globally dominant class. We present the results from the first exploratory fishing survey campaign on the CCCA, done under the regional coordination of OSPESCA (Central America Fisheries and Aquaculture Organization) on board of the R/V Miguel Oliver in January 2011. Data was collected from a total of 96 trawls arranged in 25 transects that started in Panama and finished in Belize. A Lofoten bottom trawling net was dragged for 30 min between 0 to 1500m depth. The major component of the total invertebrate catch was Holothuroidea with a biomass of 593 kg (16.49% of the total) and represented by seven species. The following are new reports for the Caribbean: Bathyplotes natans in Honduras and Guatemala, Bentothuria funebris in Panama, Benthodytes sanguinolenta in Panama, Costa Rica, Nicaragua and Belize; Hansenothuria sp. in Panama, Costa Rica and Honduras. Paroriza pallens extends its distribution to Panama, Costa Rica, Nicaragua and Honduras, Zygothuria lactea its reported in Panama. We also present the first records of the crinoid Neocomatella pulchella in Honduras, theasteroid Cheiraster (Cheiraster) planusin Panama, and, for Costa Rica (Asteroidea: Doraster constellatus and Echinoidea: Clypeaster euclastus).Holothurians are the predominant invertebrate fauna in terms of biomass in the entire region of the CCCA. These findings suggest that CCCA presents a high echinoderm biodiversity and also supports the ecoregional variation theory. We report higher echinoderm biomass (75%) in the Southwestern Caribbean compared to Western Caribbean ecoregion. The information presented in this paper establishes the baseline information of echinoderms depth fauna in the Caribbean of Central America, and opens new opportunities for future research.

Individual behaviour and resource use of thermally stressed brook trout Salvelinus fontinalis portend the conservation potential of thermal refugia.

Individual aggression and thermal refuge use were monitored in brook trout Salvelinus fontinalis in a controlled laboratory to determine how fish size and personality influence time spent in forage and thermal habitat patches during periods of thermal stress. On average, larger and more exploratory fish initiated more aggressive interactions and across all fish there was decreased aggression at warmer temperatures. Individual personality did not explain changes in aggression or habitat use with increased temperature; however, larger individuals initiated comparatively fewer aggressive interactions at warmer temperatures. Occupancy of forage patches generally declined as ambient stream temperatures approached critical maximum and fish increased thermal refuge use, with a steeper decline in forage patch occupancy observed in larger fish. These findings suggest that larger individuals may be more vulnerable to stream temperature rise. Importantly, even at thermally stressful temperatures, all fish periodically left the thermal refuge to forage. This indicates that the success of refugia at increasing population survival during periods of stream temperature rise may depend on the location of thermal refugia relative to forage locations within the larger habitat mosaic. These results provide insights into the potential for thermal refugia to improve population survival and can be used to inform predictions of population vulnerability to climate change.

Baited remote underwater video estimates of benthic fish and invertebrate diversity within the eastern Canadian Arctic

Enhanced survey efforts in the Arctic are currently needed to broaden our understanding of marine species distributions and establish the baseline data and methodologies necessary to detect potential responses to changing regional climate and human activities. For the first time, a baited remote underwater video (BRUV) survey was conducted in the Eastern Canadian Arctic, providing new biological information within data-poor regions of interest for marine conservation and potential fisheries development. A total of 31 camera deployments were conducted in 2015–2016 aboard an industry fishing vessel during summer exploratory fishing cruises, with observations occurring in the marine waters of the Qikiqtaaluk (Baffin) Region of Nunavut. In total, 18 invertebrate taxa and 14 fish taxa were observed at the baited camera, with significant differences in assemblages among sites associated with spatial variation in temperature and depth. The Greenland shark Somniosus microcephalus and polar cod Boreogadus saida were the dominant fish species observed, with the presence of brittle stars Ophiuroidea, amphipods and chaetognaths dominating invertebrate communities. Comparisons with concurrent fisheries catch data (whelk pots) demonstrated the baited camera’s ability to comparably detect local fish taxa when deployed over uniform, fine-grain sediment substrates, while local invertebrate assemblages were often better captured by fisheries surveys. These results illustrate the potential of low-impact BRUV survey methods to efficiently provide baseline data on spatial patterns of diversity and their drivers to advance our understanding of marine ecosystems within understudied polar regions.

Techno-socio-economic analysis of losses in capture fishery: a case study in Pelabuhan Ratu, Sukabumi, West Java Province

This research was aimed at analyzing factors influencing capture fisheries losses, focusing on technical, social and economic aspects at Pelabuhan Ratu. A case study was undertaken, through a survey involving 40 respondents. These respondents represented groups of fishers, collectors, middlemen, processors and consumers. The questions delivered in the survey was adapted from the Exploratory Fish Loss Assessment Method (EFLAM). Based on this research, the fish loss was detected in Palabuhan Ratu, which amounted to 4.25 % at the fisher level and 5.12 % in the following supply chains, due to some factors. It was found that among the technical factors, the most influential ones were handling of landed fish, fish sortation, fish size, fish shelf life and season. Among economic aspect, factors with the most significant influence were fish price fluctuation and price level; meanwhile, among the social factors, those that had the most significant influence was the revenue distribution system. Based on this, the relevant policy implication of this research was the need for effective programs which covers the development of cold chain and distribution facilities and infrastructure, and an improvement in skills and knowledge of fish derivative product processors.

First estimates of Greenland shark (Somniosus microcephalus) local abundances in Arctic waters

Baited remote underwater video cameras were deployed in the Eastern Canadian Arctic, for the purpose of estimating local densities of the long-lived Greenland shark within five deep-water, data-poor regions of interest for fisheries development and marine conservation in Nunavut, Canada. A total of 31 camera deployments occurred between July-September in 2015 and 2016 during joint exploratory fishing and scientific cruises. Greenland sharks appeared at 80% of deployments. A total of 142 individuals were identified and no individuals were observed in more than one deployment. Estimates of Greenland shark abundance and biomass were calculated from averaged times of first arrival, video-derived swimming speed and length data, and local current speed estimates. Density estimates varied 1–15 fold among regions; being highest in warmer (>0 °C), deeper areas and lowest in shallow, sub-zero temperature regions. These baited camera results illustrate the ubiquity of this elusive species and suggest that Nunavut’s Lancaster Sound eco-zone may be of particular importance for Greenland shark, a potentially vulnerable Arctic species.

English

The study was conducted in three districts of Western Province of Zambia namely; Mongu, Nalolo and Senanga that lie along the Zambezi River in the Barotse Floodplain. The study employed two main data tools aimed at understanding the extent of post-harvest losses in the fishing, processing and trading nodes in the fish value chain study sites. The tools were the Exploratory Fish Loss Assessment Method (EFLAM) study and a Quantitative Loss Assessment Method (QLAM) survey. The study found that physical fish losses occur at three nodes in the value chain and differ significantly (P < 0.05) between the nodes. On average, the processors lose the largest volume of fish (7.42%) followed by the fish traders (2.9%). The fishers experience the least physical losses at 2% although, this is not significantly different (P > 0.05) from the fish lost at trading node. The major cause of physical loss was found to be breakages at processing and trading nodes. There is need to introduce improved processing technologies that can reduce breakages. Furthermore, economic and nutrient losses should also be profiled to fully understand the total losses that occur within the Barotse Floodplain fish value chain. Key words: Fish, physical losses, fishing, processing, trading.

Is personality of young fish consistent through different behavioural tests?

Most studies carried out on personality recognized that personality is defined by behavioural traits consistent through time and/or contexts. In fish, most studies on personality were performed either on juveniles (aged between 6months and 1year) or adults, but very few focused on the early life stages. The main goal of this study is to characterize behavioural syndromes and to highlight the existence of a personality in young juvenile pikeperch, a species with a strong economic value. To study the consistency of behavioural responses of juvenile (50 and 64days post-hatch) pikeperch Sander lucioperca (n=41, total length=5.8±1.0cm and mass=1.6±0.7g), we performed three tests per fish in one day: exploration (cross-maze), dyadic and restraint test. In the cross-maze test, exploratory fish were more active and bolder. In the dyadic test, fish with the highest number of contacts, showed also more approaches, orientations and avoidance behaviours. In the restraint test, bolder fish were more active and tried to escape more often. Consequently, the investigation of the different behavioural responses of each fish highlighted behavioural syndromes in this species. Furthermore, for the first time, we showed, with a cross-context analysis, that young juvenile pikeperch, responded in the same way to exploration and dyadic test but their responses were opposite in the restraint test. Our results opened new opportunities for testing individual personality in very young fish that may help solving some aquaculture problems, such as intra-cohort cannibalism.

Descripción de la distribución espacial de la clorofila <i>a</i>, temperatura y salinidad en la plataforma y el talud continentales del Caribe centroamericano

Con la coordinación regional de la Organización del Sector Pesquero y Acuícola del Istmo Centroamericano (OSPESCA), se llevó a cabo del 3 de enero al 3 de febrero del año 2011 una campaña de prospección pesquera sobre la plataforma y el talud continentales del Caribe centroamericano, a bordo del B/I Miguel Oliver. En 76 estaciones hidrográficas se determinaron la temperatura, salinidad y se estimó la concentración de clorofila a través de un fluorómetro incorporado al CTD. La temperatura superficial varió entre 25 y 27°C y la salinidad en ese mismo nivel presentó valores entre 32.5 (Panamá) y 35.5 (Belice). La profundidad de la termoclina mostró una tendencia descendente de sur a norte localizándose entre los 140 y 155 m. Los valores para la concentración de clorofila a a se encuentran en el rango 0.01-1.01 mg m-3. La distribución de la clorofila a integrada en la capa de 0 a 150 m registró el valor más alto en las aguas panameñas (25.25 mg m-2), mientras la zona de Belice presentó el valor más bajo (6.05 mg m-2). Dos máximos de clorofila a (zona de mezcla y estrato termoclino) caracterizan la zona sur del Caribe centroamericano (Costa Rica y Panamá) y un único máximo ubicado cerca de los 90 m sobresale en la distribución vertical de dicha variable entre Nicaragua y Belice. La concentración de clorofila a promedio para todas las estaciones fue de 0.3 mg m-3, de modo que en la plataforma y el talud continentales predominan en general condiciones oligotróficas.

Southern elephant seals (Mirounga leonina Linn.) depredate toothfish longlines in the midnight zone.

Humans have devised fishing technologies that compete with marine predators for fish resources world-wide. One such fishery for the Patagonian toothfish (Dissostichus eleginoides) has developed interactions with a range of predators, some of which are marine mammals capable of diving to extreme depths for extended periods. A deep-sea camera system deployed within a toothfish fishery operating in the Southern Ocean acquired the first-ever video footage of an extreme-diver, the southern elephant seal (Mirounga leonina), depredating catch from longlines set at depths in excess of 1000m. The interactions recorded were non-lethal, however independent fisheries observer reports confirm elephant seal-longline interactions can be lethal. The seals behaviour of depredating catch at depth during the line soak-period differs to other surface-breathing species and thus presents a unique challenge to mitigate their by-catch. Deployments of deep-sea cameras on exploratory fishing gear prior to licencing and permit approvals would gather valuable information regarding the nature of interactions between deep diving/dwelling marine species and longline fisheries operating at bathypelagic depths. Furthermore, the positive identification by sex and age class of species interacting with commercial fisheries would assist in formulating management plans and mitigation strategies founded on species-specific life-history strategies.

Quantifying the squeezing or stretching of fisheries as they adapt to displacement by marine reserves.

The designation of no-take marine reserves involves social and economic concerns due to the resulting displacement of fishing effort, when fishing rights are removed from those who traditionally fished within an area. Displacement can influence the functioning of the fishery and success of the reserve, yet levels of displacement are seldom quantified after reserve implementation and very rarely before that. We devised a simple analytical framework based on set theory to facilitate reserve placement. Implementation of the framework requires maps of fishing grounds, fishing effort, or catch per unit effort for at least 2 years. The framework quantifies the level of conflict that a reserve designation might cause in the fishing sector due to displacement and the opportunities to offset the conflict through fisher spatial mobility (i.e., ability of fishers to fish elsewhere). We also considered how the outputs of the framework can be used to identify targeted management interventions for each fishery. We applied the method in Honduras, where the largest marine protected area in Central America is being placed, for which spatial data on fishing effort were available for 6 fisheries over 3 years. The proposed closure had a greater negative impact on the shrimp and lobster scuba fisheries, which concentrated respectively 28% and 18% of their effort inside the reserve. These fisheries could not accommodate the displacement within existing fishing grounds. Both would be forced to stretch into new fishing grounds, which are available but are of unknown quality. These stakeholders will likely require compensation to offset costly exploratory fishing or to travel to fishing grounds farther away from port.

A cascade of warming impacts brings bluefin tuna to Greenland waters.

Rising ocean temperatures are causing marine fish species to shift spatial distributions and ranges, and are altering predator-prey dynamics in food webs. Most documented cases of species shifts so far involve relatively small species at lower trophic levels, and consider individual species in ecological isolation from others. Here, we show that a large highly migratory top predator fish species has entered a high latitude subpolar area beyond its usual range. Bluefin tuna, Thunnus thynnus Linnaeus 1758, were captured in waters east of Greenland (65°N) in August 2012 during exploratory fishing for Atlantic mackerel, Scomber scombrus Linnaeus 1758. The bluefin tuna were captured in a single net-haul in 9-11 °C water together with 6 tonnes of mackerel, which is a preferred prey species and itself a new immigrant to the area. Regional temperatures in August 2012 were historically high and contributed to a warming trend since 1985, when temperatures began to rise. The presence of bluefin tuna in this region is likely due to a combination of warm temperatures that are physiologically more tolerable and immigration of an important prey species to the region. We conclude that a cascade of climate change impacts is restructuring the food web in east Greenland waters.

Reproductive Indicators and Gonad Development of the Panama Brief SquidLolliguncula panamensis(Berry 1911) in the Gulf of California, Mexico

ABSTRACT The reproductive biology of the Panama brief squid was evaluated using reproductive indicators, and histological and histochemical analyses. A total of 2,460 squid were analyzed, which were captured during 15 exploratory fishing surveys in the Gulf of California during 2003 to 2006 and 2008. Of the total sample, 61% were female, 15% were male, and the rest were undifferentiated. Based on the frequency of the gonad developmental stages, the largest number of mature females was identified in February and October, whereas mature males were found in April and August. This result coincided with the gonadosomatic index. According to the histological analyses, we characterized 4 stages of oogenesis: previtellogenesis, vitellogenesis, postvitellogenesis with mature oocytes, and postspawning. We also characterized 6 substages of oocyte and 2 structural indicators of spawning: oogonia (Po0), previtellogenic oocyte primary (Pol), previtellogenic oocyte secondary (Po2), vitellogenic primary oocyte (Vol), sec...