Study

A mark-recapture study of hatchery-reared juvenile European lobsters, Homarus gammarus, released at the rocky island of Helgoland (German Bight, North Sea) from 2000 to 2009

  • Published source details Schmalenbach I., Mehrtens F., Janke M. & Buchholz F. (2011) A mark-recapture study of hatchery-reared juvenile European lobsters, Homarus gammarus, released at the rocky island of Helgoland (German Bight, North Sea) from 2000 to 2009. Fisheries Research, 108, 22-30

Actions

This study is summarised as evidence for the following.

Action Category

Transplant/release captive-bred or hatchery-reared species - Transplant/release crustaceans

Action Link
Subtidal Benthic Invertebrate Conservation
  1. Transplant/release captive-bred or hatchery-reared species - Transplant/release crustaceans

    A study in 2000–2009 in one area of rocky seabed off Helgoland, German Bight, North Sea (Schmalenbach et al. 2011) found that after releasing one-year-old hatchery-reared European lobsters Homarus gammarus, they grew and survived in the wild, became reproductive, and appeared healthy. Recaptured lobsters had grown in the wild (females: 14.5–19.8; males: 16.8–21.8 mm/year) and reached 85 mm (legal catch size) within four to seven years after release. Survival rate of lobsters released in 2000 and 2001 was estimated at 32 and 39% respectively after up to five years. In addition, no recaptured lobsters displayed signs of “Black Spot” disease, 95% had developed a crusher-claw, and 16% of recaptured females carried eggs. Annually in 2000–2005, at two locations of 10 m water depth, tagged hatchery-reared lobsters were released at the surface (5,421 lobsters in total). Released lobsters weighed 1.5 g and had carapaces 15 mm long. Between 2000 and 2009, 488 of these were recaptured at least once, using lobster pots, traps, and divers. It is not known if the number of uncaught tagged lobsters was due to mortality, recapture effort, or migration outside the search zone. Recaptured lobsters were sexed, observed for signs of disease and presence of a crusher-claw, and their carapaces measured. Percentage survival was estimated from the mark-recapture programme data obtained between 2001 and 2005 for the 1,036 released in 2000 and 2001.

    (Summarised by: Anaëlle Lemasson)

Output references

What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, terrestrial mammals, forests, peatland and control of freshwater invasive species. More are in progress.

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

An online, free to publish in, open-access journal publishing results from research and projects that test the effectiveness of conservation actions.

Read the latest volume: Volume 18

Go to the CE Journal

Discover more on our blog

Our blog contains the latest news and updates from the Conservation Evidence team, the Conservation Evidence Journal, and our global partners in evidence-based conservation.


Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape Programme Red List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Bern wood Supporting Conservation Leaders National Biodiversity Network Sustainability Dashboard Frog Life The international journey of Conservation - Oryx British trust for ornithology Cool Farm Alliance UNEP AWFA Butterfly Conservation People trust for endangered species Vincet Wildlife Trust