Designate a Marine Protected Area and prohibit the harvesting of conch

How is the evidence assessed?
  • Effectiveness
    50%
  • Certainty
    22%
  • Harms
    12%

Source countries

Key messages

  • One study examined the effects of prohibiting the harvesting of conch in marine protected areas on their populations and/or other subtidal benthic invertebrates. The study was in the North Atlantic Ocean (British Overseas Territories).

 

COMMUNITY RESPONSE (0 STUDIES)

POPULATION RESPONSE (1 STUDY)

  • Mollusc abundance (1 study): One site comparison study in the North Atlantic Ocean found that a marine protected area prohibiting the commercial harvest of conch had more conch after five years compared to a fished area.
  • Mollusc condition (1 study): One site comparison study in the North Atlantic Ocean found that a marine protected area prohibiting the commercial harvest of conch had smaller adult conch after five years compared to a fished area.

About key messages

Key messages provide a descriptive index to studies we have found that test this intervention.

Studies are not directly comparable or of equal value. When making decisions based on this evidence, you should consider factors such as study size, study design, reported metrics and relevance of the study to your situation, rather than simply counting the number of studies that support a particular interpretation.

Supporting evidence from individual studies

  1. A site comparison study in 1998 in areas of algal seabed, sandy seabed, or seagrass bed in the North Atlantic Ocean, Turks and Caicos Islands, British Overseas Territories (Béné & Tewfik 2003) found that inside a marine protected area that had been prohibiting the commercial harvest of conch for five years, abundance of queen conch Strombus gigas was higher compared to a fished area, but effects varied with the age of conch and habitat type. Total conch abundance (juveniles and adults) was higher in the closed (555 conch/ha) compared to the fished area (277 conch/ha). Abundance of adult conch (≥4 mm lip thickness) was higher in the closed compared to the fished area for algal habitat (closed: 833 vs fished: 86) and sandy habitat (78 vs 28), but not statistically different for seagrass habitat (410 vs 24). Abundance of juvenile conch (<4 mm lip thickness) was similar inside and outside the closed area for all habitats (179–483 vs 85–497). In addition, adult conch were smaller in the closed area compared to the fished area (186 vs 204 mm shell length). In 1993 a conch sanctuary (approximately 17.5 km2) prohibiting the commercial harvest of conch was experimentally established. In June–November 1998 at an unspecified number of sites both inside and outside the sanctuary, divers counted and measured (shell length and lip thickness) all conch in 6 x 60 m transects at 0.2–12 m depth.

    Study and other actions tested
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.

Where has this evidence come from?

List of journals searched by synopsis

All the journals searched for all synopses

Subtidal Benthic Invertebrate Conservation

This Action forms part of the Action Synopsis:

Subtidal Benthic Invertebrate Conservation
Subtidal Benthic Invertebrate Conservation

Subtidal Benthic Invertebrate Conservation - Published 2020

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