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The zoantharian genus Umimayanthus consists largely of species that live in obligate symbioses with sponges. Although zoantharians have often been overlooked in field collecting campaigns and in research, sponges are usually well-collected, and many natural history museums harbor numerous sponge specimens. Thus, these sponge collections may also include previously overlooked zoantharian species. Such is the case in this research, in which we examined sponge specimens in museum collections from Western Australia and eastern Indonesia. Based on our morphological and molecular analyses, we herein describe six species of Umimayanthus new to science, and redescribe another species described over a century ago. These species can be distinguished by their sponge associations, gross polyp and colony morphology, and depth ranges. Based on these findings, it appears that the Central Indo-Pacific region of Western Australia and Indonesia can be considered a hotspot for sponge-associated zoantharian diversity. We provide a key for the identification of all formally described species in the genus, but caution that there are likely more Umimayanthus species awaiting discovery

Groundwater is a vital ecosystem of the global water cycle, hosting unique biodiversity and providing essential services to societies. Despite being the largest unfrozen freshwater resource, in a period of depletion by extraction and pollution, groundwater environments have been repeatedly overlooked in global biodiversity conservation agendas. Disregarding the importance of groundwater as an ecosystem ignores its critical role in preserving surface biomes. To foster timely global conservation of groundwater, we propose elevating the concept of keystone species into the realm of ecosystems, claiming groundwater as a keystone ecosystem that influences the integrity of many dependent ecosystems. Our global analysis shows that over half of land surface areas (52.6%) has a medium-to-high interaction with groundwater, reaching up to 74.9% when deserts and high mountains are excluded. We postulate that the intrinsic transboundary features of groundwater are critical for shifting perspectives towards more holistic approaches in aquatic ecology and beyond. Furthermore, we propose eight key themes to develop a science-policy integrated groundwater conservation agenda. Given ecosystems above and below the ground intersect at many levels, considering groundwater as an essential component of planetary health is pivotal to reduce biodiversity loss and buffer against climate change.

Oxygen depletion is well recognized for its role in the degradation of tropical coral reefs. Extreme acute hypoxic events that lead to localized mass mortality and the formation of ‘dead zones’ (a region where few or no organisms can survive due to a lack of oxygen) are particularly concerning as they can result in wide-ranging losses of biodiversity, ecosystem productivity and functioning, economic prosperity, and wellbeing. In March of 2022, the annual coral spawning event at Bills Bay (Coral Bay, Ningaloo Reef, Western Australia) coincided with elevated seawater temperature, calm weather conditions and a flood tide resulting in coral spawn becoming trapped in Bills Bay. Immediately after, there was a mass fish kill, which is believed to have been caused by local eutrophication resulting in severe oxygen depletion. The impact the deoxygenation and thermal stress event had on benthic communities has not yet been quantified; hence, the principal aim of this study is to document the extent of change that occurred in the benthic communities before and after the 2022 coral spawning event over a spatial gradient from the nearshore to mid-reef. Percent coral cover in the Bay decreased from 55.62 ± 2.26% in 2016–2018 and 70.44 ± 5.24% in 2021 to 1.16 ± 0.51% in 2022. Over the same period, the percent cover of turf algae increased from 27.40 ± 2.00% in 2016–2018 and 24.66 ± 6.67% in 2021 to 78.80 ± 3.06% in 2022, indicating a dramatic phase shift occurred at Bills Bay. The abundance of healthy coral colonies recorded on replicated belt transects at nine sites declined from 3452 healthy individuals in 2018 to 153 individuals in 2022 and coral generic richness decreased by 84.61%, dropping from 26 genera in 2018 to 4 genera in 2022. Previously dominant genera such as Acropora, Montipora and Echinopora, were extirpated from survey sites. Isolated colonies of massive Porites spp. and encrusting Cyphastrea sp. survived the event and understanding the mechanisms underpinning the

The Kimberley Marine Region is a vast stretch of complex eastern Indian Ocean seascape spanning approximately six degrees of latitude and eight degrees of longitude. The region includes various habitats, including offshore reef and shoal systems, and a complex array of nearshore platform and fringing reefs along an estimated 12,000 km of the northern Western Australian coastline. Isolated from urban centres, the Kimberley features one of the world’s least anthropogenically impacted tropical reef ecosystems and is predicted to be a signifcant repository for coral biodiversity. However, little information has been publicly available to verify this. Here we report a revision of the zooxanthellate coral biodiversity of the Kimberley region based on new specimen records. Replicate belt transects were surveyed at 135 intertidal and subtidal stations spanning the inshore, mid-shelf and offshore Kimberley from 2009–2014. Nineteen thousand and eighty-six colonies and 333 species were counted and identifed on the belt transects, and an additional 62 species were recorded incidentally off transects. Combining the new museum-accessioned specimen records with recent specimen donations and published historical records from 1893 onwards resulted in an updated regional diversity estimate of 438 species of zooxanthellate reef-building corals in the Kimberley. This dataset extends the known distribution range of 85 species, 37 of which represent new records for Australia. Our results show that the Kimberley coral communities are heterogenous, with pronounced cross-shelf, depth, and subregional diversity patterns. Ashmore Reef, Cassini Island and Montgomery Reef are regional coral biodiversity hotspots. Goniastrea retiformis, Porites lutea, Dipsastraea pallida, Goniastrea favulus and Coelastrea aspera dominate the intertidal reef zones, whilst Porites lichen, Heliopora coerulea, Seriatopora hystrix, Goniastrea pectinata and Montipora aequituberculata dominate the subtidal reefs. This

Environmental DNA (eDNA) is the fastest growing biomonitoring tool fuelled by two key features: time efficiency and sensitivity. Technological advancements allow rapid biodiversity detection at both species and community levels with increasing accuracy. Concurrently, there has been a global demand to standardise eDNA methods, but this is only possible with an in-depth overview of the technological advancements and a discussion of the pros and cons of available methods. We therefore conducted a systematic literature review of 407 peer-reviewed papers on aquatic eDNA published between 2012 and 2021. We observed a gradual increase in the annual number of publications from four (2012) to 28 (2018), followed by a rapid growth to 124 publications in 2021. This was mirrored by a tremendous diversification of methods in all aspects of the eDNA workflow. For example, in 2012 only freezing was applied to preserve filter samples, whereas we recorded 12 different preservation methods in the 2021 literature. Despite an ongoing standardisation debate in the eDNA community, the field is seemingly moving fast in the opposite direction and we discuss the reasons and implications. Moreover, by compiling the largest PCR-primer database to date, we provide information on 522 and 141 published species-specific and metabarcoding primers targeting a wide range of aquatic organisms. This works as a user-friendly ‘distillation’ of primer information that was hitherto scattered across hundreds of papers, but the list also reflects which taxa are commonly studied with eDNA technology in aquatic environments such as fish and amphibians, and reveals that groups such as corals, plankton and algae are under-studied. Efforts to improve sampling and extraction methods, primer specificity and reference databases are crucial to capture these ecologically important taxa in future eDNA biomonitoring surveys. In a rapidly diversifying field, this review synthetises aquatic eDNA procedures and can gui

Scientists and managers rely on indicator taxa such as coral and macroalgal cover to evaluate the effects of human disturbance on coral reefs, often assuming a universally positive relationship between local human disturbance and macroalgae. Despite evidence that macroalgae respond to local stressors in diverse ways, there have been few efforts to evaluate relationships between specific macroalgae taxa and local human‐driven disturbance. Using genus‐level monitoring data from 1205 sites in the Indian and Pacific Oceans, we assess whether macroalgae percent cover correlates with local human disturbance while accounting for factors that could obscure or confound relationships. Assessing macroalgae at genus level revealed that no genera were positively correlated with all human disturbance metrics. Instead, we found relationships between the division or genera of algae and specific human disturbances that were not detectable when pooling taxa into a single functional category, which is common to many analyses. The convention to use percent cover of macroalgae as an indication of local human disturbance therefore likely obscures signatures of local anthropogenic threats to reefs. Our limited understanding of relationships between human disturbance, macroalgae taxa, and their responses to human disturbances impedes the ability to diagnose and respond appropriately to these threats.