Designate a Marine Protected Area and prohibit the harvesting of sea urchins

How is the evidence assessed?
  • Effectiveness
    70%
  • Certainty
    41%
  • Harms
    0%

Source countries

Key messages

  • Two studies examined the effects of prohibiting the harvest of sea urchins in marine protected areas on their populations and/or other subtidal benthic invertebrates. Both studies were in the North Pacific Ocean (USA).

 

COMMUNITY RESPONSE (0 STUDIES)

POPULATION RESPONSE (2 STUDIES)

  • Echinoderm abundance (1 study): One replicated, site comparison study in the North Pacific Ocean found that marine protected areas prohibiting the harvest of red sea urchins had higher adult sea urchin biomass six to 33 years after their designations, compared to harvested areas.
  • Echinoderm reproductive success (1 study): One replicated, site comparison study in the North Pacific Ocean found that marine protected areas prohibiting the harvest of red sea urchins had higher urchin population reproductive biomasses, but similar reproductive indices six to 33 years after their designations, compared to harvested areas.
  • Echinoderm condition (1 study): One replicated, site comparison study in the North Pacific Ocean found that marine protected areas prohibiting the harvest of red sea urchins had bigger adult sea urchins six to 33 years after their designations, compared to harvested areas.
  • Mollusc abundance (1 study): One replicated, site comparison study in the North Pacific Ocean found that marine protected areas prohibiting the harvest of red sea urchins (year of designation unspecified) had more juvenile red abalone and juvenile flat abalone compared to harvested areas, and that juvenile abalone abundance was positively related to sea urchin abundance.

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 replicated, site comparison study in 1996–1997 of six rocky seabed sites off the coast of central and northern California, North Pacific Ocean, USA (Rogers‐Bennett & Pearse 2001) found that marine protected areas prohibiting the commercial harvest of red sea urchins Strongylocentrotus franciscanus had higher abundances of juvenile red abalone Haliotis rufescens and juvenile flat abalone Haliotis walallensis compared to areas where commercial harvesting occurred. Abundances of both species were higher in protected areas (red abalone: 8–139/plot; flat abalone: 0–18/plot) compared to harvested areas (red abalone: 0–39/plot; flat abalone: 0–9). In addition, juvenile abalone abundance was significantly positively related to sea urchin abundance, and inside protected areas 33% of juvenile abalone were found protected under sea urchin spine canopies. In October 1996 and August 1997, three marine protected areas (year of designation unspecified) prohibiting the commercial harvest of red sea urchins and three areas where urchin harvest occurred were surveyed. Juvenile red and flat abalone were counted in 24 x 30 m plots/site (5–8 m depth).

    Study and other actions tested
  2. A replicated, site comparison study in 2009–2011 of 30 sites around the Northern Channel Islands, southern California, North Pacific Ocean, USA (Teck et al. 2017) found that, six to 33 years after their designations, marine protected areas prohibiting the harvest of red sea urchin Mesocentrotus franciscanus had bigger adult urchins, higher adult total biomass and reproductive biomass, but similar urchin reproductive indices (ratio of reproductive to total biomasses), compared to sites where urchin harvest was allowed. Adult urchins diameter was 6% bigger inside the marine protected areas compared to outside. Adult total biomass was 16%, and reproductive biomass was 23% greater inside the marine protected areas compared to outside. Once a year in summer between 2009 and 2011, eleven sites within seven marine protected areas and 13 sites outside of marine protected areas were surveyed at 6 m and 13 m depths (143 surveys in total). One marine protected area was designated in 1978, and six in 2003. Despite having different levels of activity restrictions, all areas prohibited the harvest of the red sea urchin. Divers counted all urchins >25 mm test diameter along two 60 m2 transects/site/water depth. Fifteen to 20 urchins >50 mm (test diameter) were collected, measured, and their flesh and reproductive glands weighed. For each are. adult total biomass (using total urchin weight) and reproductive biomass (using urchins reproductive gland weight) were calculated from urchins count and weight data.

    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

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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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