Can we infer dredge fishing effort from macrobenthic community structure?

Abstract

Gaspar, M. B., Carvalho, S., Constantino, R., Tata-Regala, J., Cúrdia, J., and Monteiro, C. C. 2009. Can we infer dredge fishing effort from macrobenthic community structure? – ICES Journal of Marine Science, 66: 2121–2132. The effects of commercial fishing effort (FE) on macrobenthic community structure were analysed in geographically related fishing grounds separated into three groups: non-exploited (NE), moderately exploited (ME), and highly exploited (HE). Number of species, abundance, Margalef species richness, and Shannon–Wiener diversity were significantly higher in NE than in exploited areas. The first two were also significantly higher in HE than in ME areas. Measures of taxonomic diversity differed depending on whether annelids, molluscs, and crustaceans were combined or analysed separately. Crustaceans seemed to be the most vulnerable to bivalve dredging because significantly lower values were observed for them in the HE areas than in the ME and NE areas for this group. Although the samples were taken at the end of the closed season, macrobenthic communities still showed differences that may be related to FE, especially in trophic structure. Carnivory was particularly dominant in HE areas. The ratio of carnivory to filter-feeding was significantly correlated with FE, with higher values being observed in HE areas and lower values in NE areas.

Manila Clam (Tapes philippinarum Adams & Reeve, 1852) in the Lagoon of Marano and Grado (Northern Adriatic Sea, Italy): Socio-Economic and Environmental Pathway of a Shell Farm

“…Many studies have been carried out to assess the impact of fishing gear used for harvesting molluscs, particularly dredges, on bycatch species and benthic communities (e.g. Pranovi et al, 2001;Hauton et al, 2003;Gaspar et al, 2009;Leitão et al, 2009). The few studies available on the effects of commercial fishing on target species focus mainly on the qualitative/quantitative assessment of the discarded clams and on the selectivity of the fishing gear (Gaspar et al, 2003;Morello et al, 2005;Kraan et al, 2007).…”

Short term impact of artisanal dredges in a Patagonian mussel fishery: Comparisons with commercial diving and control sites

“…In more stable biogenic habitats (gravel and mud) alterations are greater and recovery rates slower than in areas of high natural disturbance which present less consolidated coarse sediments and show fewer initial effects (Kaiser et al, 2000;NRC, 2002). Then, dredging in areas of relatively high natural disturbance may have relatively short-term biological significance because of the rapid recovery of the physical environment and the biological communities (Kaiser et al, 2000;Hiddink, 2003;Gaspar et al, 2009;Constantino et al, 2009). Indeed, communities of high-stress areas (e.g., shallow areas exposed to strong tidal currents and periodic storm disturbance) have a greater capacity to readjust to the impact of dredging operations than more stable communities and recovery may be largely completed within one year (Desprez, 2000).…”

Long-term effects of fishing on physiological performance of the Manila clam (<i>Ruditapes philippinarum</i>) in the Lagoon of Venice

“…Many studies have been carried out to assess the impact of fishing gear used for harvesting molluscs, particularly dredges, on bycatch species and benthic communities (e.g. Pranovi et al, 2001;Hauton et al, 2003;Gaspar et al, 2009;Leitão et al, 2009). The few studies available on the effects of commercial fishing on target species focus mainly on the qualitative/quantitative assessment of the discarded clams and on the selectivity of the fishing gear Morello et al, 2005;Kraan et al, 2007).…”