Spatial and temporal characteristics of benthic invertebrate communities at Culbin Sands lagoon, Moray Firth, NE Scotland, and impacts of the disturbance of cockle harvesting. (original) (raw)

Mendonca VMD. 1997. Predator-prey interactions in a sandy shore system in the Moray Firth, NE Scotland. PhD Thesis in Zoology (field: Ecology). Univ Aberdeen. Aberdeen, Scotland. 202 pp. ABSTRACT: Culbin Sands is a semi-lagoon system of 1.5 ha of tidal flats, draining to the sea via a tidal gully. It has coarse sandy sediment, experiences an exposed hydrodynamic environment and is protected from the sea by a large sand dune on the seaside and a 28 ha of forest on the landwardside. As a relatively undisturbed area, it provides information useful for conservation biology, habitat management, and for better understanding of the ecology of coastal areas. Areas like Culbin are rich in epibenthic predators that use the shallow and intertidal zones as feeding grounds, as refuge from predators, or both. Many species such as flatfish and gobiids move out to the sea in autumn and return every summer in the breeding season, although the overwintering fish and shrimp that remain may also be important for the ecology of the system. Shorebirds also use the area seasonally, mainly to exploit the high abundance of food, especially during autumn and early winter. This poses the question: ‘are the effects of predation significant for their prey?’ To address this, prey and predators were regularly sampled over 1994-1996 and the effects of predators (epibenthic fauna and shorebirds) on their invertebrate prey examined using manipulative field experiments. 56 invertebrate species were identified from the sediment at Culbin. There was little evidence of consistent and easily interpretable seasonal cycles for the main invertebrates, but several species tended to have higher abundance during the autumn or early winter. Annual production by invertebrates was 15-23 g ash free dry mass (AFDM) m-2 yr-1. Arenicola marina was the most important in terms of standing stock in the sediment, followed by the bivalve Cerastoderma edule. Production values of cockles were 1.4-3.4 g AFDM m-2 yr-1. The most abundant epibenthic species were the brown shrimp Crangon crangon, the common goby Pomatoschistus microps and plaice Pleuronectes platessa, but other fish (e.g. sandeel Amodytes tobianus, three-spined stickleback Gasterosteus aculeatus, fifteen-spined stickleback Spinachia spinachia, sea scorpion Myoxocephalus scorpio, pipefish Nerophis lumbriciformis, sand goby Pomatoschistus minutus, and flounder Plactichthys flesus), crabs (e.g. shore crab Carcinus maenas and hermit crab Pagurus berhardus) and starfish Asteria rubens were also present. The most important prey were amphipods (mainly Bathyporeia spp.) for the brown shrimp and common goby, and bivalves (siphons of adult individuals) for plaice. Despite the relatively high consumption rates manipulative field experiments showed that none of the predators had significant impact on invertebrate prey densities, although shorebirds had significant size effects on the prey, especially on the larger size classes of the bivalves C. edule and Macoma balthica. These results are in line with others found all around the world such as in the Ythan estuary, Scotland (e.g. Raffaelli & Hall, 1992, Animal. Ecol. 61:551-560), USA (Wilson, 1994, J Exp Mar Biol Ecol 196:15-25), and in New Zealand (Trush et al. 1994, Mar Ecol Prog Ser 107:211-222). RESULTING PUBLICATIONS: (5) Mendonca VM, Raffaelli DG, Boyle, PR, Abella E. 2015. The role of the European brown shrimp Crangon crangon in the community ecology of a subarctic food web. Food Webs https://www.academia.edu/10413497/The\_role\_of\_the\_European\_brown\_shrimp\_Crangon\_crangon\_in\_the\_community\_ecology\_of\_a\_subarctic\_food\_web (4) Mendonca VM, Raffaelli DG, Boyle PR, Emes C. 2009. Trophodynamics in a shallow lagoon off NW Europe (Culbin Sands, Moray Firth): Spatial and temporal variability of epibenthic communities, their diets, and consumption efficiency. Zool Stud 48(2): 196-214. http://ualg.academia.edu/VandaMendon%C3%A7a/Papers/662975/Trophodynamics\_in\_a\_Shallow\_Lagoon\_off\_Northwestern\_Europe\_Culbin\_Sands\_Moray\_Firth\_Spatial\_and\_Temporal\_Variability\_of\_Epibenthic\_Communities\_Their\_ (3) Mendonca VM, Raffaelli,DG, PR Boyle, Hoskins S. 2008. Spatial and temporal characteristics of benthic invertebrate communities at Culbin Sands lagoon, Moray Firth, NE Scotland, and impacts of the disturbance of cockle harvesting. Sci Mar 72(2): 265-278. http://ualg.academia.edu/VandaMendon%C3%A7a/Papers/662982/Spatial\_and\_temporal\_characteristics\_of\_benthic\_invertebrate\_communities\_at\_Culbin\_Sands\_lagoon\_Moray\_Firth\_NE\_Scotland\_and\_impacts\_of\_the\_disturbance\_of\_cockle\_harvesting (2) Mendonca VM, Raffaelli DG, Boyle PR, Emes C. 2007. The ecological role of overwintering fish in the food web of the Culbin Sands lagoon ecosystem, NE Scotland: Identifying major trophic links and testing effects of fish Pomatoschistus microps (Pallas) on benthic invertebrates. Sci Mar 71(4): 649-660. http://ualg.academia.edu/VandaMendon%C3%A7a/Papers/662974/The\_ecological\_role\_of\_overwintering\_fish\_in\_the\_food\_web\_of\_the\_Culbin\_Sands\_lagoon\_ecosystem\_NE\_Scotland\_Identifying\_major\_trophic\_links\_and\_testing\_effects\_ (1) Mendonca VM, Raffaelli DG, Boyle PR. 2007. Interactions between shorebirds and benthic invertebrates at Culbin Sands lagoon, NE Scotland: Effects of avian predation on their prey community density and structure. Sci Mar 71(3): 579-591. http://ualg.academia.edu/VandaMendon%C3%A7a/Papers/662973/Interactions\_between\_shorebirds\_and\_benthic\_invertebrates\_at\_Culbin\_Sands\_lagoon\_NE\_Scotland\_Effects\_of\_avian\_predation\_on\_their\_prey\_community\_density\_and\_"""