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Bessey et al. present a method of passive eDNA collection from marine aquatic systems. This approach enables lower cost, high throughput sampling of aquatic environments and demonstrably collects high levels of eDNA for biodiversity studies.

Biodiversity conservation and management requires surveillance that captures the full spectrum of taxa. Here, we showcase the potential for a portfolio of visual, extractive, and molecular methods for detecting previously hidden components of tropical fish biodiversity in an economically and culturally valuable marine site that spans a tropical‐temperate ecotone—the Ningaloo Coast World Heritage Area. With scale and practicality in mind, we demonstrate how environmental DNA (eDNA) methods deployed in a stratified sampling design can yield a more comprehensive monitoring program for species presence than current alternatives (e.g., extractive sampling via anesthetic). eDNA from filtered water samples detected up to six times as many cryptobenthic fish species per site than samples collected with anesthetic, indicating it is a potentially powerful tool for assessing biodiversity of tropical fishes. However, there were also species that were only found when using anesthetic and the contribution of cryptobenthic species to overall diversity of the fish assemblage was unexpectedly low, suggesting not all cryptobenthic fish species have been detected with eDNA. There were also distinct differences in cryptobenthic assemblages both among sites and sample depths (2–3 m) when using eDNA from filtered water, suggesting this technique may be able to identify fine scale spatial differences in cryptobenthic fish assemblage. eDNA collected from water detects the most cryptobenthic species and is therefore an efficient tool for rapidly assessing biodiversity, but extractive techniques may still be required for biological and monitoring studies, and when combined with eDNA sampling provides the most comprehensive assessment of cryptobenthic fishes. [ABSTRACT FROM AUTHOR]

Coral reefs face increasing pressures in response to unprecedented rates of environmental change at present. The coral reef physical framework is formed through the production of calcium carbonate (CaCO3) and maintained by marine organisms, primarily hermatypic corals, and calcifying algae. The northern part of Western Australia, known as the Kimberley, has largely escaped land-based anthropogenic impacts and this study provides important metabolic data on reef-building organisms from an undisturbed set of marine habitats. From the reef platform of Browse Island, located on the mid-shelf just inside the 200 m isobath off the Kimberley coast, specimens of the dominant coral (six species) and algal (five species) taxa were collected and incubated ex situ in light and dark shipboard experimental mesocosms for 4 h to measure rates of calcification and production patterns of oxygen. During experimental light and dark incubations, all algae were net autotrophic producing 6 to 111 mmolO2m-2d-1. In contrast, most corals were net consumers of O2 with average net fluxes ranging from - 42 to 47 mmolO2m-2d-1. The net change in pH was generally negative for corals and calcifying algae (- 0.01 to - 0.08 h-1). Resulting net calcification rates (1.9 to 9.9 gCaCO3m-2d-1) for corals and calcifying algae (Halimeda and Galaxura) were all positive and were strongly correlated with net O2 production. In intertidal habitats around Browse Island, estimated relative contributions of coral and Halimeda to the reef production of CaCO3 were similar at around 600 to 840 gm-2yr-1. The low reef platform had very low coral cover of < 3 % which made a smaller contribution to calcification of ∼ 240 gCaCO3m-2yr-1. Calcification on the subtidal reef slope was predominantly from corals, producing ∼ 1540 gCaCO3m-2yr-1 , twice that of Halimeda. These data provide the first measures of community metabolism from the offshore reef systems of the Kimberley. The relative contributions of the main reef builders, in these undisturbed areas, to net community metabolism and CaCO3 production is important to understand exclusively climate-driven negative effects on tropical reefs. [ABSTRACT FROM AUTHOR]

Coral reefs face increasing pressures in response to unprecedented rates of environmental change at present. The coral reef physical framework is formed through the production of calcium carbonate (CaCO3) and maintained by marine organisms, primarily hermatypic corals, crustose coralline algae (CCA), and other calcifying algae. The Kimberley bioregion, located in the northern part of Western Australia, has largely escaped land-based anthropogenic impacts and this study provides important metabolic data we are lacking on reef-building calcifying corals and macrophytes from an undisturbed set of marine habitats. Specimens of the dominant coral and algal taxa were collected from the reef platform of Browse Island located on the mid-shelf just inside the 200 m isobath off the Kimberley coast. During experimental light/dark incubations, all algae were net autotrophic producing 6–111 mmol O2 m−2 day−1. In contrast, most corals were net consumers of O2 with average net fluxes ranging from −42 to 47 mmol O2 m−2 day−1. The net change in pH was generally negative for corals and calcifying algae (−0.01 to −0.08 h−1). Corals, Halimeda (a calcifying green algae) and Galaxaura (a calcifying red algae) had positive calcification rates in light ranging from 4.2 to 18.4 g CaCO3 m−2 d−1. Resulting net calcification rates were all positive and ranged from 1.9 to 9.9 g CaCO3 m−2 d−1 and were strongly correlated to net O2 production. In intertidal habitats around Browse Island, estimated relative contributions of coral and Halimeda to the reef production of CaCO3 were similar at around 600–840 g m−2 year−1. The low reef platform had very low coral cover of < 3 % which made a smaller contribution to calcification of ~240 g CaCO3 m−2 year−1. Calcification on the subtidal reef slope was predominantly from corals, producing ~1540 g CaCO3 m−2 year−1, twice that of Halimeda. The relative contributions of the main reef builders, in these undisturbed areas, to net community metabolism and CaCO3 production and reef metabolism is important to understand exclusively climate-driven coral bleaching and mortality. [ABSTRACT FROM AUTHOR]

As atmospheric CO2 levels continue to rise so too does the risk of severe impacts. Scientists clearly have an important role to play in preparing for and responding to climate change impacts; however, calls by scientists for global action have not led to the required changes. It is timely, therefore, for scientists to critically consider their own approach toward climate change research, particularly if we are to ameliorate or adapt to unwanted outcomes. Here we present three different pathways that allow scientists and scientific institutions to conceptualize the implications of their responses to climate change scenarios. These pathways are illustrated via three plausible futures for the marine environment under climate change. This approach allows future responsibilities, outcomes, and implication to be explored within and across pathways and can be applied to different scenarios for scientists and scientific institutions to anticipate and better prepare to contribute effectively to the future. Plain Language Summary: There is mounting evidence that impacts of climate change pose significant risks to society and human well‐being. The pace of large‐scale action on climate change is, however, insufficient to substantially reduce the likely future impacts. These are risks that this generation is imposing on future generations. In this context we outline a framework for scientists and scientific institutions to explore and assess the outcomes and implications of choosing different pathways (inactive, reactive, and proactive) in response to climate change. We developed three illustrative examples of plausible futures under climate change to demonstrate the implications of each of these pathways. We also outline a conceptual framework based on three factors: (i) potential to mitigate, (ii) impact of risk, and (iii) uncertainty in science that will assist scientists and scientific institutions to make informed decisions regarding their responses to global environmental change. Key Points: The implications of three pathways for scientists to respond to climate change are discussed such as maintaining trust in scienceA conceptual model is presented based on three factors: (i) potential to mitigate, (ii) impact of risk, and (iii) uncertainty in scienceA framework to assist scientists and scientific institutions to make informed decisions in response to global environmental change is outlined [ABSTRACT FROM AUTHOR]

RATIONALE Stable isotope analysis (SIA) is a powerful tool in many fields of research that enables quantitative comparisons among studies, if similar methods have been used. The goal of this study was to determine if three different drying methods commonly used to prepare samples for SIA yielded different δ15N and δ13C values. METHODS Muscle subsamples from 10 individuals each of three teleost species were dried using three methods: (i) oven, (ii) food dehydrator, and (iii) freeze-dryer. All subsamples were analysed for δ15N and δ13C values, and nitrogen and carbon content, using a continuous flow system consisting of a Delta V Plus mass spectrometer and a Flush 1112 elemental analyser via a Conflo IV universal interface. The δ13C values were normalized to constant lipid content using the equations proposed by McConnaughey and McRoy. RESULTS Although statistically significant, the differences in δ15N values between the drying methods were small (mean differences ≤0.21‰). The differences in δ13C values between the drying methods were not statistically significant, and normalising the δ13C values to constant lipid content reduced the mean differences for all treatments to ≤0.65‰. A statistically significant difference of ~2% in C content existed between tissues dried in a food dehydrator and those dried in a freeze-dryer for two fish species. There was no significant effect of fish size on the differences between methods. CONCLUSIONS No substantial effect of drying method was found on the δ15N or δ13C values of teleost muscle tissue. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Few data sets are available to evaluate short- and long-term perturbations and impacts of increasing anthropogenic stresses and a warming marine environment in coastal regions near cities. The Perth, Western Australia shoreline has extensive, depauperate sandy beaches interrupted by small, biodiverse intertidal reef platforms. We present transect data on mollusc diversity and density on three Perth platforms recorded from 1983 to 1987, and compare it to 2007 and 2021 to analyse assemblage modifications in response to increased anthropogenic pressures. NMDS multivariate analysis showed a consistent drift in assemblage composition in 2007 and 2021, but this is was not statistically significant from the 1980s baseline (PERMANOVA, P = 0.336). There was no significant long-term decline (or increase) in molluscan species richness. Most species were uncommon but eight were recorded on at least 20 of the 21 surveys. The endemic Western Australian mussel Brachidontes ustulatus (Lamarck, 1819) accounted for 71.8% of all individuals. Total mollusc density varied primarily with changes in B. ustulatus. Tropical species were a minor component of the molluscs that did not change in diversity with warming temperatures. These data provide a long-term baseline for monitoring future anthropogenic changes. [ABSTRACT FROM AUTHOR]

Rationale: Stable isotope analysis (SIA) is a powerful tool in many fields of research that enables quantitative comparisons among studies, if similar methods have been used. The goal of this study was to determine if three different drying methods commonly used to prepare samples for SIA yielded different δ(15)N and δ(13)C values., Methods: Muscle subsamples from 10 individuals each of three teleost species were dried using three methods: (i) oven, (ii) food dehydrator, and (iii) freeze-dryer. All subsamples were analysed for δ(15)N and δ(13)C values, and nitrogen and carbon content, using a continuous flow system consisting of a Delta V Plus mass spectrometer and a Flush 1112 elemental analyser via a Conflo IV universal interface. The δ(13)C values were normalized to constant lipid content using the equations proposed by McConnaughey and McRoy., Results: Although statistically significant, the differences in δ(15)N values between the drying methods were small (mean differences ≤0.21‰). The differences in δ(13)C values between the drying methods were not statistically significant, and normalising the δ(13)C values to constant lipid content reduced the mean differences for all treatments to ≤0.65‰. A statistically significant difference of ~2% in C content existed between tissues dried in a food dehydrator and those dried in a freeze-dryer for two fish species. There was no significant effect of fish size on the differences between methods., Conclusions: No substantial effect of drying method was found on the δ(15)N or δ(13)C values of teleost muscle tissue., (Copyright © 2013 John Wiley & Sons, Ltd.)