Conservation Evidence: Evidence Data

Collected Evidence: Collected Evidence: Cease or prohibit aggregate extraction Seven studies examined the effects of ceasing or prohibiting aggregate extraction on subtidal benthic invertebrate populations. One study was in the English Channel (France), one in the Mediterranean Sea (Italy), one a global study, and four in the North Sea (UK, Belgium). COMMUNITY RESPONSE (6 STUDIES) Overall community composition (4 studies): One global systematic review found that it took nine months to several decades for overall invertebrate community composition to recover after ceasing aggregate extraction. One before-and-after, site comparison study in the Mediterranean Sea and one of two site comparison studies in the North Sea found that after ceasing aggregate extraction overall invertebrate community composition became more similar to pre-extraction and/or natural site communities. Overall richness/diversity (5 studies): Two before-and-after, site comparison studies in the English Channel and the Mediterranean Sea and one of two site comparison studies in the North Sea found that after ceasing aggregate extraction, overall invertebrate species richness and/or diversity became more similar to that of pre-extraction and/or natural sites. The other site comparison found that species richness did not change over time and remained different to that of natural sites. One replicated, site comparison study in the North Sea found that 21 months after ceasing aggregate extractiom, invertebrate species richness was similar to that of natural sites. Worm community composition (1 study): One before-and-after study in the North Sea found that after ceasing aggregate extraction, nematode worm community composition remained different to the pre-extraction community. Worm richness/diversity (1 study): One before-and-after study in the North Sea found that after ceasing aggregate extraction, nematode worm species richness remained different to pre-extraction richness. POPULATION RESPONSE (6 STUDIES) Overall abundance (5 studies): Two before-and-after, site comparison studies in the English Channel and the Mediterranean Sea and one of two site comparison studies in the North Sea found that after ceasing aggregate extraction overall invertebrate abundance and/or biomass became more similar to that of pre-extraction and/or natural sites. The other site comparison found that abundance and biomass did not change over time and remained different to that of natural sites. One replicated, site comparison study in the North Sea found that 21 months after ceasing aggregate extraction, invertebrate abundance was similar to that of natural sites. Worm abundance (1 study): One before-and-after study in the North Sea found that after ceasing aggregate extraction, nematode worm abundance remained different to pre-extraction abundance. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2070https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2070Mon, 21 Oct 2019 14:07:13 +0100Collected Evidence: Collected Evidence: Extract aggregates from a vessel that is moving rather than static One study examined the effects of dredging from a vessel that is moving rather than static on subtidal benthic invertebrate populations. The study was in the English Channel (UK). COMMUNITY RESPONSE (1 STUDY) Overall species richness/diversity (1 study): One site comparison study in the English Channel found that a site where aggregate extraction was undertaken using a moving trailer suction hopper dredger had similar invertebrate species richness and lower diversity compared to a site where extraction occurred using a static suction hopper dredger. POPULATION RESPONSE (1 STUDY) Overall abundance (1 study): One site comparison study in the English Channel found that a site where aggregate extraction was undertaken using a moving trailer suction hopper dredger had higher abundance of invertebrates compared to a site where extraction occurred using a static suction hopper dredger. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2071https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2071Mon, 21 Oct 2019 14:17:57 +0100Collected Evidence: Collected Evidence: Limit, cease, or prohibit sediment discard during aggregate extraction We found no studies that evaluated the effects of limiting, ceasing, or prohibiting sediment discard during aggregate extraction on subtidal benthic invertebrate populations. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2073https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2073Mon, 21 Oct 2019 14:19:53 +0100Collected Evidence: Collected Evidence: Remove discarded sediment material from the seabed following cessation of aggregate extraction We found no studies that evaluated the effects of removing discarded sediment material from the seabed following cessation of aggregate extraction on subtidal benthic invertebrate populations. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2074https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2074Mon, 21 Oct 2019 14:36:08 +0100Collected Evidence: Collected Evidence: Cease or prohibit marine mining One study examined the effects of ceasing or prohibiting mining on subtidal benthic invertebrate populations. The study was in the Bering Sea (USA). COMMUNITY RESPONSE (1 STUDY) Overall community composition (1 study): One site comparison study in the Bering Sea found that following cessation of gold mining, overall invertebrate community composition became similar to that of an unmined site. Overall richness/diversity (1 study): One site comparison study in the Bering Sea found that following cessation of gold mining, overall invertebrate richness and diversity became similar to that of an unmined site. POPULATION RESPONSE (1 STUDY) Overall abundance (1 study): One site comparison study in the Bering Sea found that following cessation of gold mining, overall invertebrate abundance and biomass became similar to that of an unmined site. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2075https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2075Mon, 21 Oct 2019 14:43:03 +0100Collected Evidence: Collected Evidence: Cease or prohibit mining waste (tailings) disposal at sea We found no studies that evaluated the effects of ceasing or prohibiting mining waste (tailings) disposal at sea on subtidal benthic invertebrate populations. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2076https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2076Mon, 21 Oct 2019 14:43:47 +0100Collected Evidence: Collected Evidence: Leave mining waste (tailings) in place following cessation of disposal operations One study examined the effects of leaving mining waste (tailings) in place following cessation of disposal operations on subtidal benthic invertebrate populations. The study was in Auke Bay (USA). COMMUNITY RESPONSE (1 STUDY) Overall community composition (1 study): One replicated, paired, controlled study in Auke Bay found that plots where mine tailings were left in place had similar invertebrate community composition as plots where tailings had been removed, but both had different communities to plots of natural sediment. Overall richness/diversity (1 study): One replicated, paired, controlled study in Auke Bay found that plots where mine tailings were left in place had similar invertebrate species richness as plots where tailings had been removed, but both had lower richness compared to plots of natural sediment. POPULATION RESPONSE (1 STUDY) Overall abundance (1 study): One replicated, paired, controlled study in Auke Bay found that plots where mine tailings were left in place had similar invertebrate overall abundance and biomass as plots where tailings had been removed. While plots with and without tailings had similar abundances to plots of natural sediment, their biomasses were higher. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2077https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2077Mon, 21 Oct 2019 14:45:29 +0100