Benthic foraminifera as bioindicators of coral condition near mangrove environments.

Climate change stressors such as ocean warming, acidification and deoxygenation are severely threatening coral reefs and the vital ecosystem services they provide. Corals found to survive in mangrove habitats that naturally possess stressful conditions, are being increasingly studied to investigate the impact of multiple co-occurring stressors on coral growth. However, the water quality within mangrove-coral habitats and how this changes with varying distance from the mangroves remains largely unknown.

Antarctic cushion star Odontaster validus larval performance is negatively impacted by long-term parental acclimation to elevated temperature.

Cross-generational responses, when the parents' environment influences offspring performance, may contribute to species resilience to climate change in rapidly warming regions such as coastal Antarctica. Adult Antarctic sea stars Odontaster validus were conditioned in the laboratory to two temperature treatments (ambient, 0 °C and warming, +3 °C) for two years, and their gametes were used to generate larval offspring. The response of their larvae to five temperatures (0 °C, 1 °C, 2 °C, 3 °C, and 4 °C) was examined over 145 days.

Reprint: Acclimatization and Adaptive Capacity of Marine Species in a Changing Ocean.

To persist in an ocean changing in temperature, pH and other stressors related to climate change, many marine species will likely need to acclimatize or adapt to avoid extinction. If marine populations possess adequate genetic variation in tolerance to climate change stressors, species might be able to adapt to environmental change. Marine climate change research is moving away from single life stage studies where individuals are directly placed into projected scenarios ('future shock' approach), to focus on the adaptive potential of populations in an ocean that will gradually change over coming decades.

The 2024 roadmap for understanding marine species' resilience in a changing ocean.

Written to serve as a guideline for future research in this field, this roadmap provides some perspectives on the main developments and remaining challenges in the field of marine animal acclimatisation, adaptive potential and resilience to climate change. There has been extensive research conducted on the impact of climate change stress on marine animals, with studies recognising the potential for cross- and multi- generational impacts. Parents can potentially pass on resilience to offspring.

Crown-of-thorns seastar (Acanthaster spp.) feeding ecology across species and regions.

The coral predators, crown-of-thorns starfish (COTS, Acanthaster spp.) remain a major cause of extensive and widespread coral loss in Indo-Pacific coral reefs. With increased phylogenetic understanding of these seastars, at least five species appear to be present across different regions.

Untapped policy avenues to protect coral reef ecosystems.

Coral reefs are experiencing severe decline, and urgent action is required at local and global scales to curb ecosystem loss. Establishing new regulations to protect corals, however, can be time consuming and costly, and it is therefore necessary to leverage existing legal instruments, such as policies originally designed to address terrestrial rather than marine activities, to prevent coral reef degradation. Focusing on the United States, but drawing on successful examples worldwide, we present actionable pathways to increase coral protections under legislation that was originally designed to advance clean freshwater, safe drinking water, and emergency management.

Acclimation to low pH does not affect the thermal tolerance of progeny.

As the ocean warms, the thermal tolerance of marine invertebrates is key to determining their distributional change, where acclimation to low pH may impact the thermal range of optimal development. We compared thermal tolerance of progeny from a low pH-acclimated sea urchin () population from the CO vents of Ischia (Italy) and a nearby population living at ambient pH. The percentages of normally developing gastrulae and two-armed larvae were determined across 10 temperatures representing present and future temperature conditions (16-34°C).

Mapped coral mortality and refugia in an archipelago-scale marine heat wave.

Corals are a major habitat-building life-form on tropical reefs that support a quarter of all species in the ocean and provide ecosystem services to millions of people. Marine heat waves continue to threaten and shape reef ecosystems by killing individual coral colonies and reducing their diversity. However, marine heat waves are spatially and temporally heterogeneous, and so too are the environmental and biological factors mediating coral resilience during and following thermal events.

Forecasting impacts of ocean acidification on marine communities: Utilizing volcanic CO vents as natural laboratories.

Oceans have absorbed approximately 30% of anthropogenic CO emissions, causing a phenomenon known as 'ocean acidification'. With surface ocean pH changing at a rapid pace, continued uptake of CO is expected to decrease ocean pH by 0.3 pH units as early as 2081, accompanied by a decrease in the saturation of calcium carbonate minerals needed to produce skeletons and shells (RCP 8.

Impacts of pollution, fishing pressure, and reef rugosity on resource fish biomass in West Hawaii.

Human activities and land-use drivers combine in complex ways to affect coral reef health and, in turn, the diversity and abundance of reef fauna. Here we examine the impacts of different marine protected area (MPA) types, and various human and habitat drivers, on resource fish functional groups (i.e.

Responses of sea urchin larvae to field and laboratory acidification.

Understanding the extent to which laboratory findings of low pH on marine organisms can be extrapolated to the natural environment is key toward making better projections about the impacts of global change on marine ecosystems. We simultaneously exposed larvae of the sea urchin Arbacia lixula to ocean acidification in laboratory and natural CO vents and assessed the arm growth response as a proxy of net calcification. Populations of embryos were simultaneously placed at both control and volcanic CO vent sites in Ischia (Italy), with a parallel group maintained in the laboratory in control and low pH treatments corresponding to the mean pH levels of the field sites.

Limitations of cross- and multigenerational plasticity for marine invertebrates faced with global climate change.

Although cross generation (CGP) and multigenerational (MGP) plasticity have been identified as mechanisms of acclimation to global change, the weight of evidence indicates that parental conditioning over generations is not a panacea to rescue stress sensitivity in offspring. For many species, there were no benefits of parental conditioning. Even when improved performance was observed, this waned over time within a generation or across generations and fitness declined.

Cherchez la femme - impact of ocean acidification on the egg jelly coat and attractants for sperm.

The impact of ocean acidification on marine invertebrate eggs and its consequences for sperm chemotaxis are unknown. In the sea urchins and , with small (93 µm) and large (393 µm) eggs, respectively, we documented the effect of decreased pH on the egg jelly coat, an extracellular matrix that increases target size for sperm and contains sperm-attracting molecules. In near-future conditions (pH 7.

Marine gametes in a changing ocean: Impacts of climate change stressors on fecundity and the egg.

In marine invertebrates, the environmental history of the mother can influence fecundity and egg size. Acclimation of females in climate change stressors, increased temperature and low pH, results in a decrease in egg number and size in many taxa, with the exception of cephalopods, where eggs increase in size. With respect to spawned eggs, near future levels of ocean acidification can interfere with the egg's block to polyspermy and intracellular pH.

Ocean acidification has little effect on developmental thermal windows of echinoderms from Antarctica to the tropics.

As the ocean warms, thermal tolerance of developmental stages may be a key driver of changes in the geographical distributions and abundance of marine invertebrates. Additional stressors such as ocean acidification may influence developmental thermal windows and are therefore important considerations for predicting distributions of species under climate change scenarios. The effects of reduced seawater pH on the thermal windows of fertilization, embryology and larval morphology were examined using five echinoderm species: two polar (Sterechinus neumayeri and Odontaster validus), two temperate (Fellaster zelandiae and Patiriella regularis) and one tropical (Arachnoides placenta).

Increased temperature, but not acidification, enhances fertilization and development in a tropical urchin: potential for adaptation to a tropicalized eastern Australia.

To predict the effects of global change on marine populations, it is important to measure the effects of climate stressors on performance and potential for adaptation. Adaptation depends on heritable genetic variance for stress tolerance being present in populations. We determined the effects of near-future ocean conditions on fertilization success of the sea urchin Pseudoboletia indiana.

Adaptive capacity of the habitat modifying sea urchin Centrostephanus rodgersii to ocean warming and ocean acidification: performance of early embryos.

Background: Predicting effects of rapid climate change on populations depends on measuring the effects of climate stressors on performance, and potential for adaptation. Adaptation to stressful climatic conditions requires heritable genetic variance for stress tolerance present in populations.

Methodology/principal Findings: We quantified genetic variation in tolerance of early development of the ecologically important sea urchin Centrostephanus rodgersii to near-future (2100) ocean conditions projected for the southeast Australian global change hot spot.