Connectivity of larval stages of sedentary marine communities between hard substrates and offshore structures in the North Sea

Abstract

Man-made structures including rigs, pipelines, cables, renewable energy devices, and ship wrecks, offer hard substrate in the largely soft-sediment environment of the North Sea. These structures become colonised by sedentary organisms and non-migratory reef fish, and form local ecosystems that attract larger predators including seals, birds, and fish. It is possible that these structures form a system of interconnected reef environments through the planktonic dispersal of the pelagic stages of organisms by ocean currents. Changes to the overall arrangement of hard substrate areas through removal or addition of individual man-made structures will affect the interconnectivity and could impact on the ecosystem. Here, we assessed the connectivity of sectors with oil and gas structures, wind farms, wrecks, and natural hard substrate, using a model that simulates the drift of planktonic stages of seven organisms with sedentary adult stages associated with hard substrate, applied to the period 2001–2010. Connectivity was assessed using a classification system designed to address the function of sectors in the network. Results showed a relatively stable overall spatial distribution of sector function but with distinct variations between species and years. The results are discussed in the context of decommissioning of oil and gas infrastructure in the North Sea.

Marine stepping‐stones: Connectivity of Mytilus edulis populations between offshore energy installations

“…Marine stepping‐stones can be important for the distribution of native species such as Caryophyllia smithii (Coolen, Lengkeek, et al, ), Porifera sp. (van der Molen et al, ) and Desmophyllum pertusum (Henry et al, ) and most species present on offshore artificial reefs in the North Sea are indigenous for the area (Coolen et al, ; De Mesel et al, ). However, the stepping‐stone effect might also contribute to a faster distribution of nonindigenous species (Adams et al, ; IPIECA, ; Macreadie, Fowler, & Booth, ).…”

“…Populations along the North Sea shores are M. edulis (Bierne et al, 2003;Luttikhuizen, Koolhaas, Bol, & Piersma, 2002) and therefore we expected the same for the offshore North Sea. Mytilus edulis has a pelagic larval stage of 16-70 days after which the larvae metamorphose to the pediveliger stage during which it is capable of settling on suitable substrates (Bayne, 1965;Filgueira, Brown, Comeau, & Grant, 2014;van der Molen et al, 2018). In the southern North Sea, highest concentrations of M. edulis larvae are observed between March and July (P. Kamermans, Wageningen Marine Research, personal communication).…”

Upscaling positive effects of scour protection in offshore wind farms : Quick scan of the potential to upscale positive effects of scour protection on benthic macrofauna and associated fish species

“…Most studies investigating interconnectivity between offshore installations in the North Sea have been performed using larval dispersal models. To date, a limited number of studies have been published on the topic (Coolen et al, 2018a;Dannheim et al, 2018;Henry et al, 2018;Kamermans et al, 2018;van der Molen et al, 2018). Larval dispersal models use modelled water currents based on tidal currents and weather patterns from past years to hind-cast the path virtual larvae from a certain species travelled from their origin to their settlement location.…”

Social network analysis as a tool for marine spatial planning: Impacts of decommissioning on connectivity in the North Sea

“…A lack of empirical data presents a significant challenge in understanding marine connectivity. However, particle tracking models, which incorporate hydrodynamics and the biological behaviour of pelagic larvae, have been used to provide estimates of movement and connectivity via pelagic larval dispersal (Bray et al, ; Fox, Mccloghrie, Young, & Nash, ; Lacroix, Maes, Bolle, & Volckaert, ; MacLeod & Harvey, ; van der Molen et al, , ). In addition, although traditionally associated with social science, computer science and physics, social network analysis (SNA) presents a promising opportunity to examine and quantify marine connectivity.…”

“…A lack of empirical data presents a significant challenge in understanding marine connectivity. However, particle tracking models, which incorporate hydrodynamics and the biological behaviour of pelagic larvae, have been used to provide estimates of movement and connectivity via pelagic larval dispersal (Bray et al, 2017;Fox, Mccloghrie, Young, & Nash, 2006;Lacroix, Maes, Bolle, & Volckaert, 2013;MacLeod & Harvey, 2014;van der Molen et al, 2015van der Molen et al, , 2018.…”