TY - JOUR

T1 - The effects of bottom trawling and primary production on the biological traits composition of benthic assemblages

AU - Howarth, Leigh M.

AU - Waggitt, James J.

AU - Bolam, S.G.

AU - Eggleton, J

AU - Hiddink, Jan

AU - Somerfield, P.J.

PY - 2018/8/23

Y1 - 2018/8/23

N2 - Although many studies have investigated the effects of disturbance and environmental drivers on marine ecosystems, comparatively few have studied their interactions. Using fuzzy coded biological traits, we compared the functional composition, diversity and evenness of benthic communities in the English Channel and in the Celtic and Irish Seas across interacting gradients of bottom trawling and primary production. Fuzzy correspondence analysis indicated greater similarity in trait composition at sites of high trawling pressure than at those of low trawling. In contrast, the analysis revealed no relationship between trait composition and primary production. Trawling and primary production had no effect on the traits ‘longevity’, ‘sediment position’, or ‘feeding mode’. However, trawling had negative effects on all modalities within the trait ‘living habit’, and these effects were strongest for attached and epifaunal organisms but weakest for burrow- and tube-dwelling species. Trawling also negatively affected most modalities within the trait ‘maximum weight’, with strongest effects for organisms weighing between <0.1 g and up to 1 kg. Conversely, trawling positively affected organisms weighing >10 kg. For the trait ‘bioturbation’, upward conveyors were positively related with primary production, whilst other modalities exhibited no clear pattern. Because trawling affected some traits more than others, community biomass was less evenly distributed across traits in highly trawled areas, which resulted in lower levels of functional diversity and evenness. Overall, the effects of bottom trawling were greater in areas of high primary production.

AB - Although many studies have investigated the effects of disturbance and environmental drivers on marine ecosystems, comparatively few have studied their interactions. Using fuzzy coded biological traits, we compared the functional composition, diversity and evenness of benthic communities in the English Channel and in the Celtic and Irish Seas across interacting gradients of bottom trawling and primary production. Fuzzy correspondence analysis indicated greater similarity in trait composition at sites of high trawling pressure than at those of low trawling. In contrast, the analysis revealed no relationship between trait composition and primary production. Trawling and primary production had no effect on the traits ‘longevity’, ‘sediment position’, or ‘feeding mode’. However, trawling had negative effects on all modalities within the trait ‘living habit’, and these effects were strongest for attached and epifaunal organisms but weakest for burrow- and tube-dwelling species. Trawling also negatively affected most modalities within the trait ‘maximum weight’, with strongest effects for organisms weighing between <0.1 g and up to 1 kg. Conversely, trawling positively affected organisms weighing >10 kg. For the trait ‘bioturbation’, upward conveyors were positively related with primary production, whilst other modalities exhibited no clear pattern. Because trawling affected some traits more than others, community biomass was less evenly distributed across traits in highly trawled areas, which resulted in lower levels of functional diversity and evenness. Overall, the effects of bottom trawling were greater in areas of high primary production.

KW - Interactive effects

KW - Ecosystem function

KW - Fishing impacts

KW - Fuzzy coding

KW - Macroecology

KW - Multiple stressors

U2 - 10.3354/meps12690

DO - 10.3354/meps12690

M3 - Article

VL - 602

SP - 31

EP - 48

JO - Marine Ecology Progress Series

JF - Marine Ecology Progress Series

SN - 0171-8630

ER -