The European lobster is a large elongated black-blue lobster with two large claws and red antennae. One claw is sharp and small and used for slicing and the other one is for crushing their prey. The claws of the males are larger than those of the females 1,2. Their claws are exceptionally large, almost the same size as the head and the dorsal shield. They can grow to around 50 cm in size, and can become up to 20 years old, making it the oldest and largest crustacean of the North Sea. They grow at a very slow rate and reach maturity when they are 4 to 5 years old. Growing occurs by molting: first the shell is shed off, then the lobster crawls out of it, after which they swell and grow a new armor 3–5. The European lobster can make a distinction between odours and most stimulatory to them are a blend of chemicals 6.
Habitat and distribution
The European lobster prefers hard substrates like rock or hard mud and holes and crevices. They usually live in shallow waters to depths of up to 165m, usually not deeper than 50m. For food collection and nursery grounds they prefer soft substrates7–9. Adult lobsters do not travel far from their burrow because of predation or certain environmental conditions. During the moulting time lobsters defend their territorial boundary around their burrow individually. When they are in their juvenile stage they shelter communally. During the winter, they close the barrier of the burrow with sediment or debris and stay in the burrow for weeks6.
Lobsters prefer current speeds and wave energy of 0,6 m/s or lower, if it gets higher, they canget carried away10. Lobsters are distributed from the Arctic ocean in mid-Norway to the North Sea and from the north-African coast into the eastern Mediterranean5. Theoretically they could colonize the entire North Sea and use hard substrates like wrecks as stepping stones. However in practice they are more limited than their potential mobility, they mostly live in close vicinity to rocky substrates and boulder fields and since the North Sea is mostly sand and mud dominated, they need more stepping stones to enhance their connectivity than currently available11.
Food and predators
European lobster are primarily nocturnal animals and will forage during the night. As top-end predator they predate mainly on benthic invertebrates like (hermit) crabs, molluscs, echinoderms and polychaetas. Occasionally they might eat fish or algae as well. Young lobsters are preyed upon by dogfish and cod12.
Lobsters reproduce sexually, to prepare for mating; females release their pheromones into the water. Males react to this signal and compete together until the dominant male arises. They go together to a burrow to hide for predators, because the molting has made the female’s shell fragile. An important prerequisite is that the exoskeleton of the male is fully hardened when they reproduce. Fertilization can take place and the female lays her eggs. Releasing her 30,000 eggs can take from one month up to two years 6. Larvae can travel 10-100s of km with the currents, before settling. The larval stage lasts approximately one month13 . They reach maturity relatively late; after 5-10 years.
Status and protection
Around the world lobster populations have suffered due to overfishing and stock collapse, however recently they are recovering slowly in some places where management measures are applied. Partly because of their long lifespan, they are able to keep the population level sufficient3–5. In January 2002, the size of 87mm CL (Carapace Length) has become the new minimum legal catch size by the European Union. This size is equivalent to the mean size of first maturity.
The IUCN has listed the European lobster as ‘least concern’14. However, European lobster are a commercially interesting species, as well as a species benefitting from hard substrate in offshore wind farms 10,15,16. Making the habitat even more attractive for European lobster can be an easy win inside an offshore wind farm.
1. Agnalt, A.-L., Farestveit, E., Gundersen, K., Jørstad, K. E. & Kristiansen, T. S. New Zealand Journal of Marine and Freshwater Research Population characteristics of the world’s northernmost stocks of European lobster (Homarus gammarus) in Tysfjord and Nordfolda, northern Norway. J. Mar. Freshw. Res. 43, 47–57 (2010).
2. Sørdalen, T. K. et al. Harvesting changes mating behaviour in European lobster. Evol. Appl. 11, 963–977 (2018).
3. Svåsand T., Crosetti D., García-Vázquez E. & Verspoor E. (eds). Evaluation of genetic impact of aquaculture activities on native populations. (2007).
4. Wickins, J. F. & Lee, D. O. Crustacean Farming, Ranching and Culture. (Blackwell science Ltd., 2002). doi:10.1651/0278-0372(2003)023[0497:br]2.0.co;2.
5. LOBSTERS: BIOLOGY, MANAGEMENT, AQUACULTURE AND FISHERIES Edited by. (Blackwell Publishing Ltd, 2006).
7. Holthuis, L. B. FAO species catalogue Vol. 13. Marine lobsters of the world An annotated and illustrated catalogue of species of interest to fisheries known to date. FAO Fisheries Synopsis No. 125 vol. 13 (1991).
8. Lawton, P. & Lavalli, K. L. Postlarval, Juvenile, Adolescent, and Adult Ecology. in Biology of the Lobster 47–88 (Elsevier, 1995). doi:10.1016/b978-012247570-2/50026-8.
9. Jensen, A., Wickins, J. & Bannister, C. The Potential Use of Artificial Reefs to Enhance Lobster Habitat. in Artificial Reefs in European Seas (2000). doi:10.1007/978-94-011-4215-1_23.
10. Rozemeijer, M. J. C. & Van De Wolfshaar, K. E. Desktop study on autecology and productivity of European lobster (Homarus gammarus, L) in offshore wind farms. https://edepot.wur.nl/466861 (2019) doi:10.18174/466861.
11. Krone, R. & Schröder, A. Wrecks as artificial lobster habitats in the German Bight. Helgol. Mar. Res. 65, (2011).
12. Scottish Government. European lobster. https://www.webarchive.org.uk/wayback/archive/20180530011123/http://www.gov.scot/Topics/marine/marine-environment/species/fish/shellfish/EuropeanLobsterBiology.
13. Linley, E. A. ., Wilding, T. A., Black, K., Hawkins, A. & Mangi, S. Review of the reef effects of offshore wind farm structures and their potential for enhancement and mitigation. Report from PML Applications Ltd and the Scottish Association for Marine Science to the Department for Business, Enterprise and Regulatory Reform (BERR) https://tethys.pnnl.gov/sites/... (2008).
14. IUCN. Homarus gammarus (European Lobster). https://www.iucnredlist.org/sp... (2021).
15. Van Den Bogaart, L. et al. Geschiktheid zeewindparken voor maricultuur en passieve visserij: Een kwalitatieve beoordeling van geschiktheid van windparklocaties voor voedselproductie. https://doi.org/10.18174/47593... (2019) doi:10.18174/475934.
16. Van Den Bogaart, L. et al. Geschiktheid zeewindparken voor maricultuur en passieve visserij. https://doi.org/10.18174/50919... (2020) doi:10.18174/509196.