scholarly journals Effort distribution and catch patterns adjacent to temperate MPAs

2005 ◽  
Vol 62 (6) ◽  
pp. 1150-1167 ◽  
Author(s):  
Steven A. Murawski ◽  
Susan E. Wigley ◽  
Michael J. Fogarty ◽  
Paul J. Rago ◽  
David G. Mountain
Keyword(s):  
Spatial Distribution ◽  
Protected Area ◽  
Marine Protected Area ◽  
Spatial Coherence ◽  
Fishing Effort ◽  
Data Sources ◽  
Otter Trawl ◽  
Closed Area ◽  
Trawl Fishing ◽  
Average Revenue

Abstract We evaluated the spatial distribution of otter trawl fishing effort and catches resulting from the imposition in 1994 of year-round and seasonal groundfish closed areas off the NE USA. Vessel locations were available from logbooks, vessel monitoring system (VMS) data from many of the largest vessels, and from observer records. There was high spatial coherence between VMS- and observer-derived trawling locations. Prior to establishment, 31% of trawl effort (1991–1993) occurred within the 22 000 km2 of area that would eventually be closed year-round. In 2001–2003 about 10% of effort targeting groundfish was deployed within 1 km of the marine protected area (MPA) boundaries, and about 25% within 5 km. Density gradients, consistent with spill-over from MPAs, were apparent for some species. Average revenue per hour trawled was about twice as high within 4 km of the boundary, than for more distant catches, but the catch variability was greater nearer closed area boundaries. Seasonal closed areas attracted more fishing effort after opening than prior to closure even while average cpue was the same or lower. Spatial resolution of traditional data sources (e.g., logbooks) was too crude to discern detailed MPA-related effects, as revealed by high-resolution vessel positions from VMS and catch data obtained by observers.

scholarly journals Spatial distribution of otter trawl effort in Icelandic waters: comparison of measures of effort and implications for benthic community effects of trawling activities

2003 ◽  
Vol 60 (6) ◽  
pp. 1200-1215 ◽  
Author(s):  
Stefán Áki Ragnarsson ◽  
Sigmar Arnar Steingrímsson
Keyword(s):  
Spatial Distribution ◽  
Scale Effects ◽  
Benthic Communities ◽  
Demersal Fish ◽  
Fishing Effort ◽  
Otter Trawl ◽  
Community Effects ◽  
The North ◽  
Swept Area ◽  
Icelandic Waters

Abstract We examined the spatial distribution of trawling effort from logbook data from all Icelandic vessels fishing for demersal fish between 1991 and 1997 with a spatial resolution of 1 degree of latitude and 1 degree of longitude. The trawling effort was widely distributed but was intensive only in small and localised areas. Three measures of effort were compared; tow frequency, tow duration and separate estimates of swept area for otter boards and trawls. In each year, the area swept with otter trawl was 1.7 times greater than the total area in which fishing occurred over the 7 year period. In contrast, the area swept with otter boards was 4% of the total fishing area. Most of the fishing effort was confined to depths shallower than 400 m. With increasing depth, the size of trawls became larger and accordingly, also the area swept per haul. Calculations assuming no variation in the size of the trawl in relation to depth, produced inaccurate swept area estimates. Furthermore, swept area estimates based on depth corrected door spreads were greater than estimates where no such correction was made. Swept area was considered to be a more appropriate measure of effort than tow frequency and tow duration as long as variation in the size of the gear (e.g. in relation to depth) was taken into account. Effort within Icelandic waters was compared in five depth strata within seven zones. Effort was highest off the south and NW coasts and lowest off the north and east coasts. Effort was most intensive at the 100–500 m depth in all zones but in some areas (such as off NW Iceland), effort extended to deeper waters. Knowledge of the distribution of fishing effort is important for predicting larger scale effects of fishing gears on benthic communities.

scholarly journals Impacts of a novel shellfishing gear on macrobenthos in a marine protected area: pump-scoop dredging in Poole Harbour, UK

2017 ◽  
Vol 31 ◽  
pp. 5 ◽  
Author(s):  
Leo J. Clarke ◽  
Luciana S. Esteves ◽  
Richard A. Stillman ◽  
Roger J.H. Herbert
Keyword(s):  
Community Structure ◽  
Protected Area ◽  
Marine Protected Area ◽  
Fishing Effort ◽  
Economic Benefits ◽  
Manila Clam ◽  
Direct Result ◽  
Monitoring Site ◽  
Hediste Diversicolor ◽  
The Impact

Understanding the impact of bottom-fishing gears at various scales and intensities on habitats and species is necessary to inform management. In Poole Harbour, UK, a multiple use marine protected area, fishermen utilise a unique ̋“pump-scoop” dredge to harvest the introduced Manila clam Ruditapes philippinarum. Managers need to balance the socio-economic benefits of the fishery with ecological concerns across the region, which has required a revision of by-laws that include both spatial and temporal measures. Within an operational fishery, we used a Before-After-Control-Impact sampling design to assess the impacts of pump-scoop dredging on benthic physical characteristics and community structure in an area where there was no dredging, an area newly opened to dredging and an area subject to high levels of historic dredging. A sampling grid was used in each area to best capture any fishing effort in the newly opened area. Core samples were taken to a depth of 30 cm within intertidal mudflats. A significant loss of fine sediments was observed in the site subject to high intensity dredging and a significant change in community structure also occurred in both dredged sites throughout the study period. In the newly opened site this was characterised by a relative increase in species richness, including increased abundance of annelid worms, notably Hediste diversicolor and Aphelochaeta marioni and a decline in the abundance of the bivalve mollusc Abra tenuis. These changes, albeit relatively small, are attributed to physical disturbance as a direct result of pump-scoop dredging, although no difference in the classification of the biotope of the site was observed. This is of particular interest to managers monitoring site condition within areas under the new by-laws as the Manila clam is spreading to other protected estuaries in the region.

scholarly journals Effects of a large-scale and offshore marine protected area on the demersal fish assemblage in the Southwest Atlantic

2012 ◽  
Vol 70 (1) ◽  
pp. 123-134 ◽  
Author(s):  
Daniela Alemany ◽  
Oscar O. Iribarne ◽  
Eduardo M. Acha
Keyword(s):  
Fish Assemblage ◽  
Protected Area ◽  
Large Scale ◽  
Marine Protected Area ◽  
Demersal Fish ◽  
Fishing Effort ◽  
Fish Assemblage Structure ◽  
Target Species ◽  
Southwest Atlantic ◽  
Before And After

Abstract Alemany, D., Iribarne, O. O., and Acha, E. M. 2013. Effects of a large-scale and offshore marine protected area on the demersal fish assemblage in the Southwest Atlantic. – ICES Journal of Marine Science, 70:123–134. There are few extensive and offshore located marine protected areas (MPAs) in the world oceans and their performance is still being debated. We evaluated the effects of a large-scale offshore MPA located on the Southwest Atlantic Patagonian Shelf (43°S 63°W) on the demersal fish assemblage. Compliance of the Patagonian MPA was assessed by analysing eight years of satellite vessel monitoring system (VMS; 2000–2008) data, which showed compliance and fishing effort concentrated near the protection boundaries. MPA effects were studied by employing a five year database collected by a scientific research vessel in protected and fishing locations, before and after the MPA establishment. We assessed 152 scientific trawling stations using multivariate analysis of fish assemblage structure, fish abundance (discriminating target and non-target species), and mean size and proportion of juveniles of the target species (Argentine hake, Merluccius hubbsi). The identified MPA effects were a trend towards increasing abundance of the demersal fish assemblage, the target and non-target fish species, and hake juvenile size, and a higher proportion of juveniles aged 2+ inside the MPA. These positive trends support the case for offshore, large-scale MPAs.

Use of multiple data sources and analytical approaches to derive a marine protected area for a breeding seabird

2015 ◽  
Vol 191 ◽  
pp. 729-738 ◽  
Author(s):  
Martin R. Perrow ◽  
Andrew J.P. Harwood ◽  
Eleanor R. Skeate ◽  
Emilie Praca ◽  
Sarah M. Eglington
Keyword(s):  
Protected Area ◽  
Marine Protected Area ◽  
Data Sources ◽  
Multiple Data Sources ◽  
Multiple Data ◽  
Analytical Approaches

An equilibrium model for predicting the efficacy of marine protected areas in coastal environments

2007 ◽  
Vol 64 (7) ◽  
pp. 1009-1018 ◽  
Author(s):  
Carl J Walters ◽  
Ray Hilborn ◽  
Richard Parrish
Keyword(s):  
Protected Areas ◽  
Protected Area ◽  
Marine Protected Area ◽  
Critical Factor ◽  
Fishing Effort ◽  
Biological Knowledge ◽  
Juvenile Survival ◽  
Reserve Network ◽  
Stock Recruitment ◽  
Specific Alternative

Quantitative models of marine protected area (MPA) proposals can be used to compare outcomes given current biological knowledge. We used a model of a linear coastline, with 200 discrete cells each spanning 1.6 km of coast. This model is used to evaluate alternative proposals for marine protected area networks, predicting equilibrium changes in abundances and harvests while accounting for dispersal of larvae and older fish, changes in fecundity with reduced mortality in reserves, impacts of displaced fishing effort on abundances outside reserves, and compensatory (stock–recruitment) changes in postsettlement juvenile survival. The model demonstrates that modest dispersal rates of older fish can substantially reduce abundance within protected areas compared with predictions from models that ignore such dispersal. The strength of compensatory improvements in postsettlement juvenile survival is the most critical factor in determining whether a reserve network can rescue populations from the impacts of severe overharvesting. We use the model to compare specific alternative proposals for protected area networks along the California coast, as mandated through California's Marine Life Protection Act, and show that achieving the goals of the Act depends primarily on the fisheries management regulations outside of protected areas and that the size and configuration of MPAs has little impact.

scholarly journals Structure and spatio-temporal dynamics of artisanal fisheries around a Mediterranean marine protected area

2009 ◽  
Vol 67 (2) ◽  
pp. 191-203 ◽  
Author(s):  
Aitor Forcada ◽  
Carlos Valle ◽  
José L. Sánchez-Lizaso ◽  
Just T. Bayle-Sempere ◽  
Fabio Corsi
Keyword(s):  
Protected Area ◽  
Marine Protected Area ◽  
Temporal Dynamics ◽  
Marine Reserve ◽  
Fishing Effort ◽  
Western Mediterranean ◽  
Artisanal Fisheries ◽  
Time Data ◽  
Western Mediterranean Sea ◽  
Spatio Temporal

Abstract Forcada, A., Valle, C., Sánchez-Lizaso, J. L., Bayle-Sempere, J. T., and Corsi, F. 2010. Structure and spatio-temporal dynamics of artisanal fisheries around a Mediterranean marine protected area. – ICES Journal of Marine Science, 67: 191–203. Marine protected areas (MPAs) have been proposed and established throughout the world, but few studies have adequately assessed the spatial adaptations of fishers to the limitations imposed by their placement. The main objectives of this work were to identify and describe the characteristics of the artisanal fisheries around Tabarca Marine Reserve (western Mediterranean Sea) and to define their activity in space and time. Data were collected through questionnaires to fishers and onboard sampling. The artisanal fisheries were complex owing to the multispecific nature of the landings, the variety of gears involved, and their marked seasonality. All boats of the three harbours around the MPA were assessed, for a total of 32 boats. The fishers exploit 18 fishing grounds with eight gear types, for a total of 17 métiers. Mullus trammelnet, Sepia trammelnet, and sparid longline are the most frequently used métiers. The main factors determining the spatial distribution of the fishing effort are proximity to home harbour, habitat heterogeneity, and closeness to the MPA. Total fishing effort appeared slightly concentrated around the MPA, but each métier showed different patterns of effort distribution. Although the sparid gillnet and the sparid longline concentrated along MPA boundaries, the Sepia trammelnet and the Mullus trammelnet did not.

Vessel monitoring systems as a tool for mapping fishing effort for a small inshore fishery operating within a marine protected area

Marine Policy ◽  
2021 ◽  
Vol 124 ◽  
pp. 104325
Author(s):  
Sarah Elizabeth Birchenough ◽  
Patrick Arthur Cooper ◽  
Antony Charles Jensen
Keyword(s):  
Protected Area ◽  
Marine Protected Area ◽  
Fishing Effort ◽  
Monitoring Systems
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