Global significance of seagrass fishery activity Nordlund, Lina M; Unsworth, Richard K F; Gullström, Martin ...
Fish and fisheries (Oxford, England),
20/May , Volume:
19, Issue:
3
Journal Article
Peer reviewed
Open access
Seagrass meadows support fisheries through provision of nursery areas and trophic subsidies to adjacent habitats. As shallow coastal habitats, they also provide key fishing grounds; however, the ...nature and extent of such exploitation are poorly understood. These productive meadows are being degraded globally at rapid rates. For degradation to cease, there needs to be better appreciation for the value of these habitats in supporting global fisheries. Here, we provide the first global scale study demonstrating the extent, importance and nature of fisheries exploitation of seagrass meadows. Due to a paucity of available data, the study used a global expert survey to demonstrate the widespread significance of seagrass‐based fishing activity. Our study finds that seagrass‐based fisheries are globally important and present virtually wherever seagrass exists, supporting subsistence, commercial and recreational activity. A wide range of fishing methods and gear is used reflecting the spatial distribution patterns of seagrass meadows, and their depth ranges from intertidal (accessible by foot) to relatively deep water (where commercial trawls can operate). Seagrass meadows are multispecies fishing grounds targeted by fishers for any fish or invertebrate species that can be eaten, sold or used as bait. In the coastal communities of developing countries, the importance of the nearshore seagrass fishery for livelihoods and well‐being is irrefutable. In developed countries, the seagrass fishery is often recreational and/or more target species specific. Regardless of location, this study is the first to highlight collectively the indiscriminate nature and global scale of seagrass fisheries and the diversity of exploitative methods employed to extract seagrass‐associated resources. Evidence presented emphasizes the need for targeted management to support continued viability of seagrass meadows as a global ecosystem service provider.
We investigated the status and population structure of Percnon gibbesi in three areas of the island of Gran Canaria (Canary Islands, Central-East Atlantic) between July 2020 and December 2021. A ...total of 999 individuals were captured. Monthly sampling allowed us to establish the reproductive season according to the presence of ovigerous females. The methodology and number of individuals analysed were suitable for establishing the length-weight relationships and the life history parameters via modal progression analysis. The analysis of the catches per unit effort (CPUE) revealed the abundance of Percnon gibbesi in the three areas and seems to not conform with the catch quotas established in the Canary Islands Fisheries Law. Percnon gibbesi is a native crab species characteristic of intertidal and subtidal zones of the Atlantic coast of the European Macaronesian archipelagos (Azores, Madeira, and Canary Islands), and probably also in the neighbouring rocky coasts of northwest Africa. P. gibbesi is considered an invasive alien species in almost all of the Mediterranean, with expanding populations from Spain to Turkey, including Libya; However, its biology and ecology are highly unknown, despite all its range of distribution. In the intertidal zones of Gran Canaria Island, this crab, in the intertidal zones of Gran Canaria Island, shows a carapace length range between 4.1 and 22.7 mm (4.1-22.7 in males and 5.7-22.3 in females), where females showed higher weights and lengths than males on average; However, males predominated in all samples, with a sex ratio of 1:0.57. The Lsub.∞ for this crab was estimated to be 27 ± 3 mm (23 ± 4 mm for females and 25 ± 4 mm for males). The growth coefficient (K) was 0.24 yearsup.−1, the total mortality (Z) was Z = 1.71 yearsup.−1, and the natural mortality (M) was 0.47 yearsup.−1 sub.. Although females grow faster than males, males are more abundant in the larger length classes. Although the presence of ovigerous females indicated that reproduction takes place twice a year, from March to April and from August to September, the number of cohorts detected by the modal progression analysis showed that reproduction takes place all year.
Fenneropenaeus chinensis is an important economic species in the north of China, and plays an important role in both marine fishing and aquaculture. Long-term overfishing has led to the rapid decline ...of wild F. chinensis resources. The traditional trawl survey could not meet the demands of the F. chinensis resource survey. In this study, environmental DNA (eDNA) technology was used to evaluate the biomass of F. chinensis in the traditional Qinghai (Qingdao Haiyang) fishing ground in the southern sea area of the Shandong Peninsula, with the purpose of verifying whether eDNA technology can provide a new resource assessment method for fisheries resource species such as F. chinensis. The eDNA quantitative results of the Qingdao water samples ranged from 1972 copies/L to 6937 copies/L, with an average of 4366 ±1691 copies/L. Those in Haiyang water samples ranged from 4795 copies/L to 8715 copies/L, with an average of 6737 ± 1348 copies/L. The concentration of eDNA in shrimp culture ponds ranged from 1.14 × 10sup.6 copies/L to 7.61 × 10sup.6 copies/L, with an average of 3.33 × 10sup.6 ± 2.28 × 10sup.6 copies/L. The amount of eDNA released by each gram of F. chinensis per 24 h was about 2.91 × 10sup.6 copies. According to this calculation, it was estimated that the distribution of F. chinensis was about one shrimp in every 300 msup.2 sea area. Similarly, it is estimated that one shrimp is distributed every 240 msup.2 in the Haiyang sea area. The result of this study confirms the feasibility of using eDNA to evaluate the biomass of shrimps.
El año 2022 es el Año Internacional de la Pesca y la Acuicultura Artesanales. La elección de este momento pretende proporcionar un hito importante para evaluar el progreso hacia la meta de "apoyar la ...pesca a pequeña escala" y compartir buenas prácticas en todo el mundo. Sin embargo, la medición de esta meta puede resultar francamente difícil, por lo que conviene comenzar por reconocer la indudable importancia de este tipo de pesca y seleccionar los interlocutores válidos en la materia de cara a poder implementar un plan de acción válido. El momento resulta coincidente con las convocatorias en diversos países de la UE con cargo a Fondos Next Generation, que pueden contribuir a la modernización y transformación del sector, por lo que se analizan los PERTE más adecuados para el caso de España.
Abstract
As a result of the evaluation of the indicators of a large fishing enterprise of the Volga-Caspian basin (carrying out extraction and processing of biological resources), proposals were ...presented to reduce the value of the property and sources of financing of the organization, and this decrease was generally balanced with changes in revenue and profit of the enterprise. Considering the results of the analysis, as well as external and internal factors of the organization’s functioning, it is recommended to create a planning system to ensure financial stability in subsequent periods. Implementation is possible with the organization of the budgeting process. A stock management strategy was proposed to optimize their volume and structure. ABC analysis was used for this purpose, which made it possible to strengthen control over the main types of stocks and improve management efficiency. The proposed measures will facilitate the release of funds and contribute to the stabilization of the financial condition of the enterprise.
Abandoned, lost or otherwise discarded fishing gear (ALDFG) represents a significant, yet ultimately unknown amount of global marine debris, with serious environmental and socioeconomic impacts. This ...study reviews 68 publications from 1975 to 2017 that contain quantitative information about fishing gear losses. Gear loss estimates reported by the studies ranged widely, with all net studies reviewed reporting annual gear loss rates from 0% to 79.8%, all trap studies reporting gear loss rates from 0% to 88%, and all line studies reporting gear loss rates from 0.1% to 79.2%. Information obtained from this review was used to perform a meta‐analysis that provides the first synthetic, statistically robust estimates of global fishing gear losses. The meta‐analysis estimates global fishing gear losses for different major gear types. We estimate that 5.7% of all fishing nets, 8.6% of all traps, and 29% of all lines are lost around the world each year. Furthermore, we identified key gear characteristics, operational aspects and environmental contexts that influence gear loss. These estimates can be used to support sustainable fisheries development through informing risk assessments for fisheries and monitoring and assessment efforts to reduce gear losses.
Derelict fishing gear is a highly visible source of marine plastic pollution, causing mortality and ecosystem degradation with uncertain long‐term consequences. The quantity of derelict gear entering ...the oceans remains unknown because of heterogeneity in fishing gear and effort, as well as inadequate monitoring. Prior studies have been limited in scope to specific fisheries and regions, and large‐scale estimates lack an empirical basis. It is critically important for decision makers to have credible information in order to design effective remediation efforts. We estimated the amount of industrial fishing effort and the associated plastic debris entering the ocean globally each year from lost fishing gear. Using remote observations of fishing vessel activity paired with technical fishing gear models, we generated a bounding estimate for gear operation and loss worldwide in 2018. We estimate that industrial trawl, purse‐seine and pelagic longline fisheries operated 2.1 Mt of plastic gear over 2018 to obtain 49.7 Mt of retained and discarded catch, representing 74% of industrial marine capture globally. The median estimate for plastic gear lost during the use of these gear types was 48.4 kt (95% confidence interval: 28.4–99.5 kt). This estimate excludes abandoned and discarded gear. Improved observation, especially of small‐scale fisheries, is needed to better understand the sources of derelict gear. These findings serve as a benchmark for future monitoring and management efforts to reduce derelict gear in the global ocean.
This study describes the impact of the first passage of two types of bottom-towed fishing gear on rare protected shellfish-reefs formed by the horse mussel Modiolus modiolus (L.). One of the study ...sites was trawled and the other was scallop-dredged. Divers collected HD video imagery of epifauna from quadrats at the two study sites and directed infaunal samples from one site. The total number of epifaunal organisms was significantly reduced following a single pass of a trawl (90%) or scallop dredge (59%), as was the diversity of the associated community and the total number of M. modiolus at the trawled site. At both sites declines in anthozoans, hydrozoans, bivalves, echinoderms and ascidians accounted for most of the change. A year later, no recovery was evident at the trawled site and significantly fewer infaunal taxa (polychaetes, malacostracans, bivalves and ophuroids) were recorded in the trawl track. The severity of the two types of impact reflected the undisturbed status of the habitats compared to previous studies. As a 'priority habitat' the nature of the impacts described on M. modiolus communities are important to the development of conservation management policy and indicators of condition in Marine Protected Areas (EU Habitats Directive) as well as indicators of 'Good Environmental Status' under the European Union Marine Strategy Framework Directive. Conservation managers are under pressure to support decisions with good quality evidence. Elsewhere, indirect studies have shown declines of M. modiolus biogenic communities in fishing grounds. However, given the protected status of the rare habitat, premeditated demonstration of direct impact is unethical or illegal in Marine Protected Areas. This study therefore provides a unique opportunity to investigate the impact from fishing gear whilst at the same time reflecting on the dilemma of evidence-based conservation management.
PDF
