Importance of predation by crustaceans upon bivalve spat in the intertidal zone of the Dutch Wadden Sea as revealed by immunological assays of gut contents

Predation and habitat modification synergistically interact to control bivalve recruitment on intertidal mudflats

“…Marine bivalves typically have an opportunistic reproductive strategy, releasing large numbers of eggs per individual (>1 million) into the water column (mainly in spring), where they are externally fertilized (Honkoop and van der Meer, 1998). The settlement location and subsequent survival of the bivalves in the following months, are notoriously unpredictable and variable between years in soft-sediment systems like the Wadden Sea (van der Veer et al, 1998;Brinkman et al, 2002). Apart from environmental factors (e.g., temperature, hydrodynamics, substrate conditions), it has been suggested that biotic interactions like chemical cues are important to initiate settlement (Dobretsov and Wahl, 2001;Liu et al, 2011).…”

“…Apart from environmental factors (e.g., temperature, hydrodynamics, substrate conditions), it has been suggested that biotic interactions like chemical cues are important to initiate settlement (Dobretsov and Wahl, 2001;Liu et al, 2011). Once settled, overall recruitment success of bivalves in intertidal areas is considered to be depend on many different factors, including abiotics, predation and facilitation effects (van der Veer et al, 1998;Brinkman et al, 2002;Strasser, 2002;Schulte et al, 2009;Troost, 2010). Our experimental findings suggest that these factors are not only important, but that they can strongly interact to control bivalve recruitment dynamics, potentially explaining in part the difficulties in predicting bivalve recruitment success in soft-sediment systems.…”

“…Apart from deteriorated substrate conditions, predation pressure by crustaceans is increasing in many coastal areas, often due to overfishing of top-predators resulting in mesopredator release (Worm and Myers, 2003). In the Dutch Wadden Sea, shrimp numbers are over twice as high compared to other European coastal waters (Tulp et al, 2012), peaking in summer at over 100 individuals/m 2 on intertidal flats (van der Veer et al, 1998). Furthermore, shore crab densities increased over 10-fold since 1995, with numbers still rising (Tulp et al, 2012).…”

“…In this study, we therefore investigated the importance of predation, habitat modification and their interplay in explaining bivalve recruitment dynamics in the intertidal of the Wadden Sea. Predation during high tide by brown shrimp (Crangon crangon) and shore crab (Carcinus maenas) has been suggested to have a strong negative effect on bivalve recruitment in soft-sediment systems (van der Veer et al, 1998;Strasser, 2002). Next to predation, biotic habitat modification could be an important driver for recruitment as well, because such mechanisms can cause strong facilitation effects in coastal ecosystems (Bruno et al, 2003;Eriksson et al, 2010).…”

Crayfish Predation Experiments on the Introduced Zebra Mussel, Dreissena Polymorpha, in Ireland, and Their Potential for Biocontrol.

“…VAN DER VEER et al (1998) demonstrated predation on bivalve spat (or post-veliger mussels) by brown shrimps, Crangon crangon and shore crabs in the Dutch Wadden Sea. Although juvenile crayfish can filter-feed (HOLDICH and LOWERY, 1988), it has yet to be demonstrated if zebra mussel spat would succumb to similar crayfish predation.…”