Movement of wild European lobsters Homarus gammarus in natural habitat

Abstract

Most previous mark-recapture studies of the movement of European lobsters have used externally attached tags which were lost at ecdysis, restricting the range of possible recapture intervals. Published studies of this species with tags designed to be retained through ecdysis have focussed on artificially reared lobsters, or wild lobsters released in artificial habitat. Here, we report a mark-recapture study of the mobility of wild European lobsters conducted in 3 areas on the south coast of England, using persistent tags. Tagged lobsters were smaller than the fishery minimum landing size (50 to 84 mm carapace length) and were therefore likely to be predominantly sexually immature. The majority of these lobsters do not appear to undertake extensive alongshore or on-/offshore migrations. Recapture distances ranged from 0 to 45 km, but 95% of recaptured lobsters moved < 3.8 km from their original release positions over periods of up to 862 d. Distance moved did not differ between males and females, but there was a weak positive relationship between recapture distance and body size. The directional distribution of movements > 0.5 km differed between the 3 study areas and appeared to be related to the spatial configuration of local lobster habitat, but with a marked tendency for offshore movement in 2 of the areas. Movements > 5 km from all 3 release areas, which comprised 5% of recaptures after > 6 mo, were generally undertaken by larger lobsters and were almost exclusively to the west or southwest, against the general direction of tide-and wind-generated residual water movement in the English Channel.

Fine-scale movement, activity patterns and home-ranges of European lobster Homarus gammarus

“…Only a small number of individuals have been observed to travel up to 15 km in a season (Thomas 1954, Simpson 1961. Furthermore, movements and distributions are largely influenced by the spatial distribution of hard substrates, interpreted by positions of capture and recaptures, and often re flected in the distribution of commercial fishing effort (Smith et al 2001). However, CMR studies are impeded by low tag-returns, a lack of fine-scale resolution and only provide discrete positional data at the time of capture.…”

“…This is particularly true for the European lobster Homarus gammarus (Smith et al 2001), despite it being one of the most valuable commercial species in the UK (Marine Management Organisation 2013). Lobsters are considered nocturnal (Smith et al 1998) and cannot physically regulate their body temperature; therefore, warmer temperatures and periods of darkness are thought to produce greatest movements.…”

“…(1) lobster home-ranges and movements were restricted to hard substrate; (2) the greatest space-utilisation and distances travelled were displayed by large, male lobsters, based on previous findings suggesting males are more 'risk-taking' and the weak positive relationship between size and distance travelled (Jensen et al 1994, Rowe 2001, Smith et al 2001, Wiig et al 2013; and (3) movement and space-use vary between seasons and over the diel cycle, with dark and warm periods leading to greatest movements.…”

“…Lobsters are considered nocturnal (Smith et al 1998) and cannot physically regulate their body temperature; therefore, warmer temperatures and periods of darkness are thought to produce greatest movements. Previous analyses using capture-mark-recapture (CMR), with the primary goal of estimating mortality or growth rates of H. gammarus, have provided limited movement data that suggest H. gammarus has restricted movements; < 3 km for periods of up to a year (Jensen et al 1994, Smith et al 2001, Jørstad et al 2004, Agnalt et al 2007). H. gammarus are generally believed to make short random movements away from shelter, which could be prompted by local competition for food, shelter and mates (Pawson 1995).…”

“…AT reduces the re liance upon baitedtraps, which are constrained by issues of variable effort, catchability and trap saturation; these issues have historically hindered the robustness of findings. Despite the obvious advantages, AT has not yet been applied to crustaceans in the UK (Guerra-Castro et al 2011), where movement and space-utilisation remain poorly investigated (but see Smith et al 1998Smith et al , 2001. AT and data storage tags have been applied to H. gammarus on 3 occasions in Norway (van der Meeren 1997, Moland et al 2011a, Wiig et al 2013).…”