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Context. Global and local stressors can drive phase shifts from zooxanthellate scleractinian coral communities to macroalgae-dominated ecosystems. However, our understanding of altered ecosystem functioning, productivity and stability remains limited as pre-shift data are typically lacking for degraded coral-reef sites. Aims. Here, we assessed functional changes in fish communities in Nakagusuku Bay, Okinawa, Japan, over 45 years, by comparing pre-disturbance (1975) to postdisturbance (2018-2020) datasets, and identified possible drivers of changes. Methods. We analysed data for 393 fish species and 26 coral genera at 13 sites, measured at four-time points (1975, 2018, 2019 and 2020). Analyses were performed using a range of ordination techniques. Key results. We found reductions in functional richness and trait space contraction over time for fishes. Changes in coral functional groups over time correlated with changes in the functional diversity of reef-fish communities; a reduction in branching corals reduced habitat availability for coral-reliant fishes. Conclusions. Increasing sedimentation and eutrophication as a result of construction along the Nakagusuku Bay coast likely reduced living coral cover and fish diversity, and thermal stress likely facilitated the simplification and shifts of both coral communities and coral specialist fishes away from shore. Implications. Both global and local threats need to be considered when assessing functioning of coral-reef ecosystems for coral-reef conservation efforts. [ABSTRACT FROM AUTHOR]

The term Marine Animal Forest (MAF) was first described by Alfred Russel Wallace in his book "The Malay Archipelago" in 1869. The term was much later re-introduced and various descriptions of MAFs were presented in great detail as part of a book series. The international research and conservation communities have advocated for the future protection of MAFs and their integration into spatial plans and, in response, there are plans to include the characteristics of MAFs into national policies and international directives and conventions (i.e. IUCN, CBD, OSPAR, HELCOM, Barcelona Convention, European directives, ABJN policies etc.). Some MAF ecosystems are already included in international and national conservation and management initiatives, for instance, shallow water coral reefs (ICRI, ICRAN) or cold-water coral reefs and gardens and sponge aggregations (classified as Vulnerable Marine Ecosystems, VMEs), but not as a group together with other ecosystems with similar ecological roles. Marine Animal Forests can be found in all oceans, from shallow to deep waters. They are composed of megabenthic communities dominated by sessile suspension feeders (such as sponges, corals and bivalves) capable of producing three-dimensional frameworks with structural complexity that provide refuge for other species. MAFs are diverse and often harbour highly endemic communities. Marine animal forests face direct anthropogenic threats and they are not protected in many regions, particularly in deep-sea environments. Even though MAFs have been already described in detail, there are still fundamental knowledge gaps regarding their geographical distribution and functioning. A workshop was dedicated to clarifying the definition of MAFs, characterising their structure and functioning, including delineating the ecosystem services that they provide and the threats upon them. The workshop was organised by Working Group 2 of the EU-COST Action "MAF-WORLD" (hereafter WG2), which is responsible for collating and promoting research on mapping, biogeography and biodiversity of MAFs, to identify and reduce these knowledge gaps. Herein, we report on this workshop and its outputs. [ABSTRACT FROM AUTHOR]

Masashi Yomogida, Masaru Mizuyama, Toshiki Kubomura, and James Davis Reimer (2017) Terpios hoshinota is cyanobacteriosponge that can cause serious damage to coral reef ecosystems by undergoing rapid breakouts in which it smothers and encrusts hard substrates, killing living sessile benthic organisms and reducing biodiversity of the a ected area. The reasons for these outbreaks are still unclear, as are long-term prognoses of affected reefs. Some reports have suggested outbreaks may not be permanent, but very little long-term monitoring information exists. In this study, we report on a T. hoshinota outbreak (~24% coverage) at Yakomo, Okinoerabu-jima Island, Kagoshima, Japan between 2010 to 2014. In this period, the existing outbreak was seen to almost completely disappear (~0%) after unusually severe Typhoon Songda passed by in early June 2011. After this, macroalgae and a cyanobacterial bloom became the dominant benthos, but by September 2014, T. hoshinota coverage had recovered to approximately half of its pre-typhoon coverage, suggesting the conditions that had caused the outbreak still persisted at Yakomo. While the conditions promoting T. hoshinota growth at this site remain uncertain, it appears that subtropical typhoons could play an important role in the dynamics of T. hoshinota outbreaks and disappearances.