Intensity Of Fishing Activity Research Articles

Modelling the distribution of fishing-related floating marine litter within the Bay of Biscay and its marine protected areas

Sea-based sources account for 32–50 % of total marine litter found at the European basins with the fisheries sector comprising almost 65 % of litter releases. In the south-east coastal waters of the Bay of Biscay this figure approaches the contribution of just the floating marine litter fraction. This study seeks to enhance knowledge on the distribution patterns of floating marine litter generated by the fisheries sector within the Bay of Biscay and in particular on target priority Marine Protected Areas (MPAs) to reinforce marine litter prevention and mitigation policies. This objective is reached by combining the data on geographical distribution and intensity of fishing activity, long-term historical met-ocean databases, Monte Carlo simulations and Lagrangian modelling with floating marine litter source and abundance estimates for the Bay of Biscay. Results represent trajectories for two groups of fishing-related items considering their exposure to wind; they also provide their concentration within 34 MPAs. Zero windage coefficient is applied for low buoyant items not subjected to wind effect. Highly buoyant items, strongly driven by winds, are forced by currents and winds, using a windage coefficient of 4 %. Results show a high temporal variability on the distribution for both groups consistent with the met-ocean conditions in the area. Fishing-related items driven by a high windage coefficient rapidly beach, mainly in summer, and are almost non-existent on the sea surface after 90 days from releasing. This underlines the importance of windage effect on the coastal accumulation for the Bay of Biscay. Only around 20 % of particles escaped through the boundaries for both groups which gives added strength to the notion that the Bay of Biscay acts as accumulation region for marine litter. MPAs located over the French continental shelf experienced the highest concentrations (>75 particles/km2) suggesting their vulnerability and need for additional protection measures.

Macro-, meso- and microplastic debris in the beaches of Tuticorin district, Southeast coast of India

This study investigates the mean concentration and characteristics of macroplastics (>2.5 cm), mesoplastics (5 mm - 2.5 cm) and microplastics (<5 mm) on eight sandy beaches along the shoreline of Tuticorin, Tamil Nadu. Prevalence of plastic litters varies among the study sites depending on the intensity of fishing and other human activities. Mean concentrations of macroplastics (1.38 ± 78 to 6.16 ± 94 items/m2), mesoplastics (2 ± 0.8 to 17 ± 0.11 items/m2) and microplastics (25 ± 1.58 to 83 ± 49 items/m2) were estimated in respect of the polymers composing them namely PE, PP, PET, NY, PS and PVC, of which PE is the most predominant polymer. At Sites 1, 2, 3, 5 and 8 there is correlation between the intensity of fishing activity and the concentrations of macro- (p = 0.02) and microplastics (p = 0.03). Sites 4, 6 and 7 there is correlation established between the degree of recreational activity and the concentrations of meso- (p = 0.02) and microplastics (p = 0.01).

Filling the gap: Using fishers’ knowledge to map the extent and intensity of fishing activity

Knowledge of the extent and intensity of fishing activities is critical to inform management in relation to fishing impacts on marine conservation features. Such information can also provide insight into the potential socio-economic impacts of closures (or other restrictions) of fishing grounds that could occur through the future designation of Marine Conservation Zones (MCZs). We assessed the accuracy and validity of fishing effort data (spatial extent and relative effort) obtained from Fishers’ Local Knowledge (LK) data compared to that derived from Vessel Monitoring System (VMS) data for a high-value shellfish fishery, the king scallop (Pecten maximus L.) dredge fishery in the English Channel. The spatial distribution of fishing effort from LK significantly correlated with VMS data and the correlation increased with increasing grid cell resolution. Using a larger grid cell size for data aggregation increases the estimation of the total area of seabed impacted by the fishery. In the absence of historical VMS data for vessels ≤15 m LOA (Length Overall), LK data for the inshore fleet provided important insights into the relative effort of the inshore (<6 NM from land) king scallop fishing fleet in the English Channel. The LK data provided a good representation of the spatial extent of inshore fishing activity, whereas representation of the offshore fishery was more precautionary in terms of defining total impact. Significantly, the data highlighted frequently fished areas of particular importance to the inshore fleet. In the absence of independent sources of geospatial information, the use of LK can inform the development of marine planning in relation to both sustainable fishing and conservation objectives, and has application in both developed and developing countries where VMS technology is not utilised in fisheries management.

Mapping fisheries for marine spatial planning: Gear-specific vessel monitoring system (VMS), marine conservation and offshore renewable energy

Vessel Monitoring System (VMS) data from 2005 to 2008 in ICES Divisions VIIe-h were used to assess the distribution and intensity of fishing activity in and around the western English Channel, one of the most intensively used marine areas on the planet. The distribution of the UK fleet of large (>15m length) fishing vessels was analysed and clear gear-specific temporal and spatial differences in activity were found. Mobile demersal gears had the highest intensity and widest distribution of activity in the study area, and so might be expected to have the most widespread ecosystem-level impacts. The potential effects of two proposed fisheries closures; a planned wave energy testing facility (Wave Hub) and a candidate offshore Marine Protected Area (Haig Fras) are described. Maps indicate that mobile demersal gear fleets would be little affected if they were excluded from these proposed closures, but if the static gear fleets were excluded this would likely result in displacement of certain vessels, increasing fishing pressure on other rocky grounds and other fishers. Predictions concerning the effects of fisheries displacement can be improved through the use of high-resolution gear-specific activity data. This study shows that VMS can provide an invaluable source of such data, provided that gear information is made available to fisheries managers and scientists.

Scavenging on trawled seabeds can modify trophic size structure of bottom-dwelling fish

Abstract Shephard, S., Minto, C., Zölck, M., Jennings, S., Brophy, D., and Reid, D. 2014. Scavenging on trawled seabeds can modify trophic size structure of bottom-dwelling fish. – ICES Journal of Marine Science, 71: 398–405. Disturbance by towed bottom-fishing gears often kills larger sensitive benthos, leading to changes in the abundance, size, and species composition of benthic communities. Short-term availability of trawl-damaged prey, and longer-term shifts in benthic prey community composition, both have the potential to affect feeding opportunities and realized dietary preferences of bottom-feeding (benthivorous) fish. To investigate these effects of bottom-fishing activity (by otter trawls, beam trawls, and dredges) on the feeding of benthivorous fish, we compared the trophic level at body size and diets of four species in areas of the Celtic Sea subject to low, intermediate, and high fishing activity. Trophic level was estimated using nitrogen stable isotope analysis, and fishing activity was quantified with vessel monitoring system (VMS) data. For whiting (Merlangius merlangus) of all sizes, trophic level was slightly lower in areas of higher fishing activity. After accounting for the results of the diet analysis, we concluded that this reflected increased scavenging of benthic invertebrates in more intensively fished areas. For megrim (Lepidorhombus whiffiagonis), the rate of increase in trophic level with size was lower with increasing fishing activity, implying that megrim may also substitute fish with lower-trophic invertebrates that can be scavenged in more intensively fished areas. For plaice (Pleuronectes platessa) and lemon sole (Microstomus kitt), no significant effects of fishing activity on trophic level were detected. We conclude that differences in the intensity of fishing activity with towed bottom gears had small but variable effects of the trophic size structure of the four species, and that this primarily reflected scavenging rather than diet changes following longer-term shifts in composition of the prey community.

Implications of using alternative methods of vessel monitoring system (VMS) data analysis to describe fishing activities and impacts

Abstract Lambert, G. I., Hiddink, J. G., Hintzen, N. T., Hinz, H., Kaiser, M. J., Murray, L. G., and Jennings, S. 2012. Implications of using alternative methods of vessel monitoring system (VMS) data analysis to describe fishing activities and impacts. – ICES Journal of Marine Science, 69: 682–693. Understanding the spatial distribution and intensity of fishing activity is a prerequisite for estimating fishing impacts on seabed biota and habitats. Vessel monitoring system data provide information on fishing activity at large spatial scales. However, successive position records can be too infrequent to describe the complex movements fishing vessels make. High-frequency position data were collected to evaluate how polling frequency and the method of analysis influenced the estimates of fishing impact on the seabed and associated epifaunal communities. Comparisons of known positions with predictions from track interpolation revealed that the performance of interpolation depended on fleet behaviour. Descriptions and indicators of fishing intensity were influenced significantly by the analytical methods (track reconstruction, density of position records) and grid-cell resolution used for the analysis. These factors can lead to an underestimation of fishing impact on epifaunal communities. It is necessary to correct for such errors to quantify the effects of fishing on various ecosystem components and hence to inform ecosystem-based management. Polling at intervals of 30 min would provide a desirable compromise between achieving precise estimates of fishing impacts on the seabed and minimizing the cost of data collection and handling.

PENANGGULANGAN TERHADAP KEGIATAN ILLEGAL FISHING OLEH KAPAL-KAPAL PENANGKAP IKAN ASING DI WILAYAH PANTAI BARAT SUMATERA

The intensity of fishing activity around West Coast Area of Sumatra increased along with the decrease of the fish amount in marine area in other countries. This condition urged foreign fisherman boats to search for a new fishing area including the West Coast Area of Sumatra. This Area was the strategic part of marine area of Indonesia, it directly faced the high seas, Indian Ocean. Based on the data from Department of Maritime Affairs and Fisheries, marine fishery source of Indonesia was estimated to reach 6.167.940 tons per year. This illegal fishing was certainly detrimental for the country since it threatened the fishery potentials and the fish stock was decreasing. The line of West Coast Area of Sumatra was prone with illegal fishing, which included West Sumatera, Nanggroe Aceh Darussalam, and North Sumatera. The illegal fishing activities in the West Coast of Sumatra had been apprehensive, because the waters around this area were the open sea easily entered by foreign boats. Therefore, “Fishery Court” (in Medan) was formed to investigate, adjudicate, and decide criminal offense in fishery. The fishermen caught and arrested were then processed further based on the law referring to the Act No. 8 of 1981 on KUHP. Key Words: The Tackling, Illegal Fishing, West Coast Area of Sumatra