Conservation Evidence strives to be as useful to conservationists as possible. Please take our survey to help the team improve our resource.

Providing evidence to improve practice

Action: Designate a Marine Protected Area and prohibit commercial fishing Subtidal Benthic Invertebrate Conservation

Key messages

Read our guidance on Key messages before continuing

  • Three studies examined the effects of prohibiting commercial fishing in marine protected areas on subtidal benthic invertebrates. Two studies were in the South Pacific Ocean (New Zealand), and one in the Caribbean Sea (Mexico).

 

COMMUNITY RESPONSE (0 STUDIES)

POPULATION RESPONSE (3 STUDIES)

  • Crustacean abundance (2 studies): Two replicated studies (one before-and-after, one site comparison) in the South Pacific Ocean found that after implementing a marine park prohibiting commercial fishing but allowing the recreational harvest of lobsters, lobster abundance inside the park did not increase over the 12 years after implementation, and abundance was similar inside the park and outside where fishing occurred.
  • Crustacean condition (3 studies): One replicated, before-and-after study in the South Pacific Ocean found that over the 12 years after implementing a marine park prohibiting commercial fishing but allowing the recreational harvest of lobsters, the biomass of legal-size lobsters inside the park did not increase. One of two site comparison studies (one replicated) in the South Pacific Ocean and the Caribbean Sea found bigger lobsters in an area closed to commercial fishing for an unspecified amount of time compared to a fished area. The second study found that 10 years after implementing a marine park prohibiting commercial fishing but allowing the recreational harvest of lobsters, lobster size was similar inside the park and outside where fishing occurred.

BEHAVIOUR (1 STUDY)

  • Crustacean behaviour (1 study): One site comparison study in the Caribbean Sea found that 80% of the lobster population occurring in a protected area (year of designation unspecified) where commercial fishing was prohibited remained in the unfished area, and thus remained protected.

Supporting evidence from individual studies

1 

A replicated, before-and-after study in 1977–2005 of nine rocky seabed sites in the South Pacific Ocean, north-eastern New Zealand (Shears et al. 2006a) found that over the 12 years after implementing a marine park prohibiting commercial fishing but allowing the recreational harvest of spiny lobsters Jasus edwardsii, abundance and biomass of lobsters inside the park did not increase. Average lobster abundance was statistically similar before (7–47 lobsters/transect) and 12 years after implementation (4–9). Average biomass of legal-size lobsters (>95 mm carapace length) was similar before (1–3 kg/transect) and after implementation (0–1). Mimiwhangata Marine Park was established in 1984 (implemented 1993). Between 1977 and 2005, nine sites inside the park were surveyed annually. Divers counted all lobsters and visually estimated the size and weight of legal-size lobsters along one 50 x 10 m transect/site.

 

A replicated, site comparison study in 2003 of 17 rocky seabed sites in the South Pacific Ocean, north-eastern New Zealand (Shears et al. 2006b) found that 10 years after implementing a marine park prohibiting commercial fishing but allowing the recreational harvest of spiny lobsters Jasus edwardsii, abundance and size of lobsters were not higher inside the park compared to outside where fishing occurred. Lobster abundance was not different inside (24 lobsters/transect, of which 8 were legal-sized) and outside the park (28 lobsters/transect, of which 6 were legal-sized). The carapace length of lobsters was not different inside (82 mm) and outside (88 mm) the park. Mimiwhangata Marine Park was established in 1984 (implemented 1993). In 2003, nine sites inside the park and eight fully-fished sites outside were surveyed. Divers counted and visually estimated the size of lobsters along three 50 x 10 m transects/site.

2 

A site comparison study in 2011–2012 of two areas in the Caribbean Sea, Mexico (Ley‐Cooper et al. 2014) found that Carribbean spiny lobsters Panulirus argus grew larger in an area where commercial fishing was banned compared to a fished area, and that a high proportion of the lobster population in the unfished area stayed there over the duration of the study and thus remained protected. Lobster sizes were greater in the unfished area (94 mm) compared to the fished area (73 mm). In the unfished area, this corresponded to 99% of lobsters being bigger than the minimum legal catch size (74.5 mm), while in the fished area it corresponded to only 25%. In addition, an estimated 20% of the lobster population occurring in the unfished area moved to the fished area over the duration of the study, thus 80% remained protected inside the unfished area. The study was carried out in a Biosphere Reserve (year of designation unspecified) which restricted commercial fishing to shallow depths (<20 m) and banned it where depths exceed 20 m (see paper for details). In August–September 2011, lobsters were hand-caught from the unfished area, tagged, sized (carapace length) and released in the unfished area (379 in total). During the 2011/2012 fishing season in the fished area, all lobsters caught by fishermen were sized, and tagged lobsters recorded. A tag-recapture model based on the number of recaptured tagged lobsters (20 in total) was used to estimate the percentage of the lobster population moving from the protected to the fished area.

Referenced papers

Please cite as:

Lemasson, A.J., Pettit, L.R., Smith, R.K., and Sutherland, W.J. (2019) Subtidal Benthic Invertebrate Conservation: Global Evidence for the Effects of Interventions. Synopses of Conservation Evidence Series. University of Cambridge, Cambridge, UK.