Likely to be beneficial

Designate a Marine Protected Area and introduce some fishing restrictions (types unspecified)

1Four studies examined the effects of introducing unspecified types of fishing restrictions in marine protected areas on subtidal benthic invertebrate populations. Two studies were in the Indian Ocean (Seychelles), one was a global systematic review, and one was in the Mediterranean Sea (Italy). COMMUNITY RESPONSE (2 STUDIES)

2Overall community composition (2 studies): One of two site comparison studies (one replicated) in the Indian Ocean and the Mediterranean Sea found that a marine protected area with unspecified fishing restrictions (year of designation unspecified) had a different combined invertebrate and algae community composition, while the other (time since designation unspecified) found similar compositions compared to fished areas.

3POPULATION RESPONSE (3 STUDIES)

4Overall abundance (1 study): One replicated, site comparison study in the Mediterranean Sea found that a marine protected area with unspecified fishing restrictions had similar invertebrate abundance compared to unprotected fished areas (time since designation unspecified).

5Bryozoan abundance (1 study): One site comparison study in the Indian Ocean found that a marine protected area with unspecified fishing restrictions (year of designation unspecified) had similar abundance of bryozoans compared to fished areas.

6Crustacean abundance (1 study): One global systematic review found that marine protected areas with unspecified fishing restrictions had more lobsters compared to fished areas.

7Echinoderm abundance (2 studies): One of two site comparison studies (one replicated) in the Indian Ocean found that marine protected areas with unspecified fishing restrictions had more sea cucumbers after more than 20 years but the other found fewer sea lilies (year of designation unspecified) compared to fished areas.

8Hydrozoan abundance (1 study): One site comparison study in the Indian Ocean found that a marine protected area with unspecified fishing restrictions (year of designation unspecified) had more hydrozoans compared to fished areas.

9Mollusc abundance (1 study): One global systematic review found that marine protected areas with unspecified fishing restrictions had more scallops compared to fished areas.

10Sponge abundance (1 study): One site comparison study in the Indian Ocean found that a marine protected area with unspecified fishing restrictions (year of designation unspecified) had more sponges compared to fished areas.

11Tunicate abundance (1 study): One site comparison study in the Indian Ocean found that a marine protected area closed to fishing with unspecified fishing restrictions (year of designation unspecified) had similar abundance of ascidians/sea squirts (tunicates) compared to fished areas.

12Assessment: likely to be beneficial (effectiveness 50 %; certainty 40 %; harms 0 %).

https://www.conservationevidence.com/actions/2239

Designate a Marine Protected Area and prohibit all types of fishing

13Thirty studies examined the effects of prohibiting all types of fishing in marine protected areas on subtidal benthic invertebrate populations. Four studies were systematic reviews of marine reserves (New Zealand and across the world). Two studies were in the North Atlantic Ocean (Bahamas). Five were in the South Pacific Ocean (New Zealand, French Polynesia). Three were in the North Pacific Ocean (USA). Seven were in the Tasman Sea (New Zealand, Australia). One was in the Florida Keys (USA). One was in the Coral Sea (Australia). Three were in the Mediterranean Sea (Italy, Spain). One was in the Bristol Channel and the Irish Sea (UK). Two were in the Firth of Clyde (UK). One was in the Foveaux Straight (New Zealand).

14COMMUNITY RESPONSE (5 STUDIES)

15Overall community composition (3 studies): Three site comparison studies (one replicated and paired, one replicated, one paired) in the Mediterranean Sea, the Tasman Sea, and the Firth of Clyde found that marine protected areas that had been prohibiting all fishing for five to 16 years depending on the study, had similar combined algae, invertebrate and fish community composition, similar combined mollusc and echinoderm community composition, and similar overall community composition of large invertebrates but different composition of small sessile invertebrates, compared to fished areas.

16Overall species richness/diversity (5 studies): One global systematic review, and three site comparison studies (one replicated and paired, one replicated, one paired) in the Mediterranean Sea, the Tasman Sea, and the Firth of Clyde found that marine protected areas that had been prohibiting all fishing for five to 16 years depending on the study, had similar overall invertebrate species richness/diversity, similar combined algae, invertebrate and fish species richness, and similar combined mollusc and echinoderm species richness, compared to fished areas. One site comparison study in the Tasman Sea found inside a marine protected area prohibiting all mobile fishing that macroinvertebrate species richness remained stable over the 15 years after its designation and enforcement, but decreased at fished sites.

17POPULATION RESPONSE (2 STUDIES)

18Overall abundance (4 studies): Two systematic reviews of marine protected areas across the world prohibiting all fishing found that they had greater overall invertebrate abundance and biomass compared to fished areas. Two site comparison studies (one before-and-after, one replicated) in the Tasman Sea found that inside marine protected areas prohibiting all fishing, overall invertebrate abundance did not change over the 15 years after their designation and enforcement and that it did not change in fished areas either, and that all areas had similar combined mollusc and echinoderm abundance after 16 years.

19Overall condition (1 study): One global systematic review found that in marine protected areas prohibiting all fishing, invertebrates were bigger compared to fished areas.

20Crustacean abundance (17 studies): Two reviews (one global and systematic, one of New Zealand areas) found that marine protected areas prohibiting all fishing had more lobsters compared to marine protected areas only partially prohibiting fishing and unrestricted fished areas. Eleven of 15 site comparison studies (including replicated, randomized, paired, before-and-after) in the North Atlantic Ocean, the Bristol Channel and the Irish Sea, the Firth of Clyde, the Mediterranean Sea, the North Pacific Ocean, the Florida Keys, the South Pacific Ocean, the Tasman Sea, and the Coral Sea found that inside marine protected areas prohibiting all fishing, the abundances and/or biomasses of lobsters and mud crabs were higher compared to areas where seasonal or unrestricted fishing was allowed, after four to 33 years depending on the study. Four found that they had mixed effects on the abundances of lobster, and crab species, after one to seven years depending on the study. Two found that they had similar abundance of lobsters compared to fished areas after either five to seven years or after approximately 30 years.

21Crustacean reproductive success (4 studies): Two site comparison studies (one replicated, randomized) in the Florida Keys and the Firth of Clyde found that marine protected areas prohibiting all fishing and harvesting had similar population sex ratios of lobsters compared to where seasonal fishing or all fishing was allowed, after four to seven years depending on the study. Two replicated, site comparison studies (one randomized) in the Tasman Sea and the Mediterranean Sea found that marine protected areas prohibiting all fishing had greater lobster egg production potential compared to commercial fishing exclusion zones and fully fished areas, after either 15 years or 21 to 25 years. One site comparison study in the Firth of Clyde found that marine protected areas prohibiting all fishing had more female lobsters with eggs than fished areas, after four to seven years.

22Crustacean condition (8 studies): One review of studies in New Zealand, and five of seven site comparison studies (four replicated, one replicated and randomized) in the North Atlantic Ocean, the Bristol Channel and the Irish Sea, the Firth of Clyde, the Florida Keys, the South Pacific Ocean, the Coral Sea, and the Tasman Sea, found that marine protected areas prohibiting all fishing had bigger lobsters and crabs compared to seasonally fished or fully fished areas, after four to seven years depending on the study. Three found mixed effects on lobsters and crabs depending on species, sex, and locations, after one to seven years depending on the study.

23Crustacean population structure (2 studies): Two replicated site comparison studies (one randomized) in the Tasman Sea and the Mediterranean Sea found that marine protected areas prohibiting all fishing had different population size structures of lobsters compared to commercial fishing exclusion zones (only for females) and compared to fished areas, after either 15 years or 21 to 25 years.

24Echinoderm abundance (3 studies): Two of three site comparison studies (two replicated, one paired) in the North Pacific Ocean, the South Pacific Ocean, and the North Pacific Ocean, found that marine protected areas prohibiting all fishing had similar abundance of Kina sea urchins after more than 10 years, and sea cucumbers after eight years to fished areas, and a third found higher abundance of red sea urchins after approximately 30 years. One also found that the effects on abundance of red sea urchins depended on the age of the protected area and the size of the urchins.

25Echinoderm condition (1 study): One paired, site comparison study in the South Pacific Ocean found that marine protected areas that had been prohibiting all fishing for over 10 years had heavier Kina sea urchins compared to fished areas.

26Mollusc abundance (10 studies): Four of 10 site comparison studies (including replicated before-and-after, and site comparison) in the North Atlantic Ocean, the North Pacific Ocean the South Pacific Ocean, the Tasman Sea, and the Foveaux Straight found that inside a marine reserve prohibiting all fishing, abundances/biomass of giant clams, adult queen conch, Cook’s turban snails, rock scallops and green abalone were higher compared to a fished area, after eight to 36 years depending on the study. Six found similar abundances of scallop species, pink abalone, juvenile queen conch, and top shell species, after five to 36 years depending on the study. Three found lower abundances of star limpets after 23 to 25 years and blacklip abalone after 15 to 16 years. One found that the effects of marine protected areas prohibiting all fishing on the abundance of mussel species compared to a commercial fishing exclusion zone varied with the age and location of the protected areas.

27Mollusc reproductive success (1 study): One site comparison study in the North Atlantic Ocean found that inside a marine protected area that had been prohibiting all fishing for 33 to 36 years, abundance of queen conch larvae was higher compared to an unprotected fished area.

28Mollusc condition (1 study): One site comparison study in the North Pacific Ocean found that in marine protected areas that had been prohibiting all fishing pink abalone were bigger five to 23 years after their designation, compared to fished site.

29Assessment: likely to be beneficial (effectiveness 59 %; certainty 60 %; harms 0 %).

http://www.conservationevidence.com/actions/2224

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

30Two 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).

31COMMUNITY RESPONSE (0 STUDIES)

32POPULATION RESPONSE (2 STUDIES)

33Echinoderm 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.

34Echinoderm 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.

35Echinoderm 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.

36Mollusc 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. Assessment: likely to be beneficial (effectiveness 70 %; certainty 41 %; harms 0 %).

https://www.conservationevidence.com/actions/2238

Designate a Marine Protected Area with a zonation system of activity restrictions

37Thirteen studies examined the effects of designating a marine protected area with a zonation system of activity restrictions on subtidal benthic invertebrate populations. Four studies were in the Caribbean Sea (Belize, Mexico), three in the Mediterranean Sea (Italy), one in the Central Pacific Ocean (Ecuador), three in the Bristol Channel and the Irish Sea (UK), one in the Indian Ocean (Australia), and one in the North Atlantic Ocean (Portugal).

38COMMUNITY RESPONSE (2 STUDIES)

39Overall community composition (1 study): One site comparison study in the Mediterranean Sea found that inside a marine protected area with a zonation system, the combined invertebrate and algae species community composition was different at a site prohibiting all fishing compared to sites where some fishing occurs, after six years.

40Overall species richness/diversity (1 study): One site comparison study in the North Atlantic Ocean found that inside a marine protected area with a zonation system, sites prohibiting nearly all fishing had similar invertebrate species richness to sites where fishing was mostly allowed, after two years. POPULATION RESPONSE (13 STUDIES)

41Overall abundance (1 study): One site comparison study in the North Atlantic Ocean found that inside a marine protected area with a zonation system, abundances of specific invertebrate groups varied between sites prohibiting nearly all fishing and sites where fishing was mostly allowed, after two years. Crustacean abundance (7 studies): Three of seven site comparison studies (two replicated) in the Caribbean Sea, the Central Pacific Ocean, and in the Bristol Channel and the Irish Sea found that inside a marine protected area with a zonation system, abundance and/or biomass of spiny lobsters increased in a zone closed to all/commercial fishing and were greater than in a zone where fewer fishing restrictions occurred, after four to 20 years depending on the study. One found that sites closed to all fishing had higher abundances of spiny lobsters and slipper lobsters after eight to ten years compared to fished sites. Two found that sites closed to all fishing for six to seven years had more European lobsters than sites where potting was allowed. And one found that abundances of European lobsters, velvet crabs, brown crabs and spider crabs, after one to four years, varied with the levels of protection.

42Crustacean condition (4 studies): Three of five site comparison studies (one replicated) in the Bristol Channel and the Irish Sea, and in the Caribbean Sea found that, inside a marine protected area with a zonation system, sites prohibiting all fishing for seven years or commercial fishing (duration unspecified) had bigger lobsters compared to fished areas. One found that the sizes of lobsters, velvet crabs, brown crabs and spider crabs varied with the levels of protection, and one study found that the size of spiny lobsters decreased similarly in an area prohibiting all fishing and in an area with fewer restrictions 14 to 20 years after designation of the protected area. Two studies undertaken in the same area found conflicting effects of prohibiting all fishing for six to seven years on disease and injury of lobsters.

43Echinoderm abundance (2 studies): One of two site comparison studies in the Mediterranean Sea found that inside a marine protected area with a zonation system, at a site prohibiting all fishing for 17 to 18 years, abundances of two species of sea urchins were higher than at sites allowing the recreational fishing of purple sea urchins. The other one found similar abundance of purple sea urchins inside fully protected sites, sites where some restricted urchin harvest occurs, and unprotected fished sites outside the protected area after five years.

44Echinoderm condition (2 studies): Two site comparison studies in the Mediterranean Sea found that inside a marine protected area with a zonation system, sites prohibiting all fishing had bigger sea urchins compared to sites where some restricted urchin harvest occurs and compared to unprotected fished sites outside the protected area, after either four years or 17 to 18 years. Mollusc abundance (3 studies): One replicated, randomized, controlled study in the Indian Ocean found that inside a marine protected area with a zonation system, abundance of blacklip abalone was higher in sites that had been prohibiting all fishing for five years compared to those prohibiting commercial fishing only. Two site comparison studies in the Caribbean Sea found that inside marine protected areas with a zonation system, abundances of adult queen conch increased over time in a zone closed to all fishing and were greater than in zones with fewer restrictions, but abundances of juvenile conch did not differ or vary differently between zones, after either five to eight years or 14 to 20 years.

45Mollusc condition (1 study): One site comparison study in the Caribbean Sea found that inside a marine protected area with a zonation system, the size of queen conch decreased similarly in the area prohibiting all fishing and in the area with fewer restrictions, after 14 to 20 years.

46Sponge abundance (1 study): One site comparison study in the Mediterranean Sea found that inside a marine protected area with a zonation system, the cover of sponges Cliona was higher at a site prohibiting all fishing for six years compared to sites where some fishing occurred.

47BEHAVIOUR (1 STUDY)

48Crustacean behaviour (1 study): One site comparison study in the Caribbean Sea found that, inside a marine protected area with a zonation system (year of designation unspecified), 80 % of the lobster population occurring in the unfished area remained in the protected unfished area, and thus remained protected.

49Assessment: likely to be beneficial (effectiveness 60 %; certainty 60 %; harms 10 %).

http://www.conservationevidence.com/actions/2230

Unknown effectiveness

Designate a Marine Protected Area and install physical barriers to prevent trawling

50One study examined the effects of installing physical barriers to prevent trawling in a protected area on subtidal benthic invertebrate populations. The study was in the South China Sea (Hong Kong).

51COMMUNITY RESPONSE (1 STUDY)

52Worm community composition (1 study): One replicated, site comparison study in the South China Sea found that sites in a protected area where physical barriers were installed to prevent trawling had a different community composition of nematode worms compared to nearby unprotected fished sites, after up to two years.

53Worm species richness/diversity (1 study): One replicated, site comparison study in the South China Sea found that sites in a protected area where physical barriers were installed to prevent trawling had similar diversity and species richness of nematode worms to nearby unprotected fished sites, after up to two years.

54POPULATION RESPONSE (1 STUDY)

55Overall abundance (1 study): One replicated, site comparison study in the South China Sea found that sites in a protected area where physical barriers were installed to prevent trawling had fewer small invertebrates compared to nearby unprotected fished sites, after up to two years.

56Worm abundance (1 study): One replicated, site comparison study in the South China Sea found that sites in a protected area where physical barriers were installed to prevent trawling had fewer nematode worms compared to nearby unprotected fished sites, after up to two years.

57Assessment: unknown effectiveness (effectiveness 30 %; certainty 30 %; harms 10 %).

https://www.conservationevidence.com/actions/2227

Designate a Marine Protected Area and only allow hook and line fishing

58One study examined the effects of allowing only hook and line fishing in marine protected areas on subtidal benthic invertebrate populations. The study was in the Skagerrak (Norway).

59COMMUNITY RESPONSE (0 STUDIES)

60POPULATION RESPONSE (1 STUDY)

61Crustacean abundance (1 study): One replicated, controlled, before-and-after study in the Skagerrak found that sites inside a protected area only allowing hook and line fishing had greater increases in lobster abundance over the four years after the area was designated compared to unprotected fully fished sites.

62Crustacean condition (1 study): One replicated, controlled, before-and-after study in the Skagerrak found that sites inside a protected area only allowing hook and line fishing had greater increases in lobster size over the four years after the area was designated compared to unprotected fully fished sites. Assessment: unknown effectiveness (effectiveness 75 %; certainty 32 %; harms 0 %).

https://www.conservationevidence.com/actions/2233

Designate a Marine Protected Area and prohibit all towed (mobile) fishing gear

63Two studies examined the effects of prohibiting all towed gear in marine protected areas on subtidal benthic invertebrate populations. One study was in the Bristol Channel and the Irish Sea (UK), the other in the English Channel (UK).

64COMMUNITY RESPONSE (1 STUDY)

65Overall community composition (1 study): One before-and-after, site comparison study in the English Channel found that, over the three years after closing a marine protected area to all towed gears, the community composition of reef-indicative invertebrate species became different to that of unprotected fished sites.

66Overall diversity/species richness (1 study): One before-and-after, site comparison study in the English Channel found that, over the three years after closing a marine protected area to all towed gears, the number of reef-indicative invertebrate species remained similar to unprotected fished sites. POPULATION RESPONSE (2 STUDIES)

67Overall abundance (1 study): One before-and-after, site comparison study in the English Channel found that, over the three years after closing a marine protected area to all towed gears, the abundance of reef-indicative invertebrate species became greater than at unprotected fished sites.

68Crustacean abundance (1 study): One replicated, site comparison study in the Bristol Channel and the Irish Sea found that a marine protected area closed to all towed gear (only allowing potting) for 33 to 36 years had mixed effects on the abundances of lobsters and crabs depending on species.

69Crustacean condition (1 study): One replicated, site comparison study in the Bristol Channel and the Irish Sea found that a marine protected area closed to all towed gear (only allowing potting) for 33 to 36 years had mixed effects on the sizes of lobsters and crabs depending on species.

70Assessment: unknown effectiveness (effectiveness 45 %; certainty 23 %; harms 10 %).

https://www.conservationevidence.com/actions/2229

Designate a Marine Protected Area and prohibit aquaculture activity

71One study examined the effects of prohibiting aquaculture activity in a protected area on subtidal benthic invertebrate populations. The study was in Tapong Bay lagoon (Taiwan).

72COMMUNITY RESPONSE (0 STUDIES)

73POPULATION RESPONSE (1 STUDY)

74Crustacean abundance (1 study): One before-and-after study in Tapong Bay lagoon found that two and a half years after removing oyster aquaculture in a marine protected area, the biomasses of amphipods and shrimps had decreased, and that the biomass of crabs had not changed.

75Mollusc abundance (1 study): One before-and-after study in Tapong Bay lagoon found that two and a half years after removing oyster aquaculture in a marine protected area, the biomasses of gastropods and bivalves had decreased.

76Worm abundance (1 study): One before-and-after study in Tapong Bay lagoon found that two and a half years after removing oyster aquaculture in a marine protected area, the biomass of polychaete worms had stayed the same.

77Assessment: unknown effectiveness (effectiveness 40 %; certainty 10 %; harms 20 %).

https://www.conservationevidence.com/actions/2240

Designate a Marine Protected Area and prohibit bottom trawling

78Three studies examined the effects of prohibiting bottom trawling in marine protected areas on subtidal benthic invertebrates. Two studies were in the South Pacific Ocean (Australia) and one in the Coral Sea (Australia).

79COMMUNITY RESPONSE (3 STUDIES)

80Overall community composition (2 studies): One of two replicated, site comparison studies in the South Pacific Ocean found that seamounts within a protected area closed to trawling had different invertebrate community composition compared to trawled seamounts and to never-trawled seamounts after four to nine years. The second study found that seamounts within a protected area closed to trawling had different invertebrate community composition compared to shallow unprotected seamounts (heavily trawled) after two years, but not compared to deep unprotected seamounts (lightly trawled).

81Overall diversity/species richness (3 studies): One of two replicated, site comparison studies in the South Pacific Ocean found that seamounts within a protected area closed to trawling had similar invertebrate species richness and diversity to trawled seamounts and never-trawled seamounts after four to nine years. The second study found that seamounts within a protected area closed to trawling had more invertebrate species compared to shallow unprotected seamounts (heavily trawled) after two years, but not compared to deep unprotected seamounts (lightly trawled). One randomized, replicated, site comparison study in the Coral Sea found similar combined invertebrate and fish species richness in areas closed to trawling and adjacent fished areas, after seven to eight years.

82POPULATION RESPONSE (3 STUDIES)

83Overall abundance (3 studies): One of two replicated, site comparison studies in the South Pacific Ocean found that seamounts within a protected area closed to trawling had lower invertebrate biomass compared to trawled seamounts and never-trawled seamounts after four to nine years. The second study found that seamounts within a protected area closed to trawling had higher invertebrate biomass compared to shallow unprotected seamounts (heavily trawled) after two years, but not compared to deep unprotected seamounts (lightly trawled). One randomized, replicated, site comparison study in the Coral Sea found similar invertebrate and fish biomass in areas closed to trawling and adjacent fished areas, after seven to eight years.

84Assessment: unknown effectiveness (effectiveness 50 %; certainty 22 %; harms 0 %).

https://www.conservationevidence.com/actions/2226

Designate a Marine Protected Area and prohibit commercial fishing

85Three 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)

86POPULATION RESPONSE (3 STUDIES)

87Crustacean 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.

88Crustacean 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.

89BEHAVIOUR (1 STUDY)

90Crustacean 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.

91Assessment: unknown effectiveness (effectiveness 35 %; certainty 30 %; harms 0 %).

https://www.conservationevidence.com/actions/2225

Designate a Marine Protected Area and prohibit dredging

92One study examined the effects of prohibiting dredging in marine protected areas on subtidal benthic invertebrates. The study was in the Firth of Lorn (UK).

93COMMUNITY RESPONSE (1 STUDY)

94Overall community composition (1 study): One paired, replicated, site comparison study in the Firth of Lorn found that sites inside a protected area that had been prohibiting dredging for approximately 2.5 years had different combined invertebrate and fish community composition compared to unprotected dredged sites.

95POPULATION RESPONSE (1 STUDY)

96Overall abundance (1 study): One paired, replicated, site comparison study in the Firth of Lorn found that sites inside a protected area that had been prohibiting dredging for approximately 2.5 years typically had greater combined cover of bryozoans and hydroids (combined) compared to unprotected dredged sites.

97Assessment: unknown effectiveness (effectiveness 60 %; certainty 20 %; harms 0 %).

https://www.conservationevidence.com/actions/2228

Designate a Marine Protected Area and prohibit the harvesting of conch

98One 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).

99COMMUNITY RESPONSE (0 STUDIES)

100POPULATION RESPONSE (1 STUDY)

101Mollusc 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.

102Mollusc 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. Assessment: unknown effectiveness (effectiveness 50 %; certainty 22 %; harms 12 %).

https://www.conservationevidence.com/actions/2237

Establish community-based fisheries management

103One study examined the effects of establishing community-based fisheries management on subtidal benthic invertebrate populations. The study was in the Foveaux Straight (New Zealand).

104COMMUNITY RESPONSE (0 STUDIES)

105POPULATION RESPONSE (1 STUDY)

106Mollusc abundance (1 study): One replicated, site comparison study in the Foveaux Straight found that a customary fisheries area where management was community-based had more New Zealand scallops compared to a protected area prohibiting all fishing and an area allowing recreational harvest.

107Mollusc condition (1 study): One replicated, site comparison study in the Foveaux Straight found that a customary fisheries area where management was community-based, tended to have smaller New Zealand scallops compared to a protected area prohibiting all fishing and an area allowing recreational harvest.

108Assessment: unknown effectiveness (effectiveness 45 %; certainty 21 %; harms 0 %).

https://www.conservationevidence.com/actions/2242

No evidence found (no assessment)

109We have captured no evidence for the following interventions:

• Designate a Marine Protected Area and limit the density of traps

• Designate a Marine Protected Area and limit the number of fishing vessels

• Designate a Marine Protected Area and prohibit static fishing gear

• Designate a Marine Protected Area and prohibit the harvesting of scallops

• Designate a Marine Protected Area and set a no-anchoring zone

• Designate a Marine Protected Area without setting management measures, usage restrictions, or enforcement

• Designate a Particularly Sensitive Sea Area (PSSA) to regulate impactful maritime activities

• Engage with stakeholders when designing Marine Protected Areas.