Recruitment of crustose coralline algae on tiles material for monitoring coral larvae settlement’s consolidators at Nature Reserve Pulau Sempu, East Java, Indonesia

Crustose coralline algae (Corallinophycideae) are red algae that produced calcium carbonate and are well recognized as foundation species in the epipelagic zone of the marine ecosystem. These algae induced settlement juvenile of coral by released chemical cues from bacterial communities on the surface of their colonies. Their extracellular calcium carbonate also can stabilize reef structure that influencing many invertebrate attaches and growth in the seabed. Crustose coralline algae (CCA) have obtained attention because of their distribution and health compromise to increasing seawater temperature, ocean acidification, and pollutant. As a cryptic species in the ecosystem, the presence of CCA recruit sometimes doesn’t have attention, especially on their capability to occupy the empty space. This study aimed to document coverage and number of CCA recruit in two different recruitment tile’s material. The highest CCA percentage of the cover was showed inside surface than others surface in all stations. Light intensity and low sedimentation were suggested as a key factor of success of high coverage. Overall, station higher CCA recruits have shown from Tiga Warna. Low sedimentation and protection from aerial exposure became the main reason for it. No significant difference number of CCA recruits between marble and sandstone in this study. Successful CCA recruitment in this study can give a wide picture that natural recruitment of coral and other reef biodiversity in Southern Malang might be will succeed because of the abundance of coralline algae that support their life history stage.

Effect of species, size, and chimerism on the susceptibility of Caribbean brain coral recruits to stony coral tissue loss disease (SCTLD)

Stony coral tissue loss disease (SCTLD) has devastated coral populations along Florida′s Coral Reef and beyond. Although widespread infection and mortality of adult colonies have been documented, no studies have yet investigated the susceptibility of recruits to this disease. Here, we exposed eight-month-old Diploria labyrinthiformis recruits and four-month-old Colpophyllia natans recruits to two sequential doses of SCTLD in the laboratory to track infection and assess potential resilience. Both species began to develop lesions as early as 48 h after exposure began. During the first dose, 59.0% of C. natans recruits lost all tissue (died) within two to eight days of developing lesions, whereas D. labyrinthiformis recruits experienced significantly slower rates of tissue loss and minimal eventual mortality. In C. natans, larger recruits and those fused into groups of multiple genets (chimeras) exhibited the highest survivorship. In contrast, smaller and/or single (ungrouped) recruits had the lowest survivorship (9.9 - 26.5%). After 20 days, a second SCTLD dose was delivered to further test resistance in remaining recruits, and all recruits of both species succumbed within 6 days. Although no recruits showed absolute resistance to SCTLD following repeated exposures, our results provide evidence that interactions between species, size, and chimerism can impact relative resistance. This study represents the first report of SCTLD in Caribbean coral recruits and carries implications for natural species recovery and reef restoration efforts. Additional research on the susceptibility of coral juveniles to SCTLD is urgently needed, to include different species, locations, parents, and algal symbionts, with the goal of assessing relative susceptibility and identifying potential sources of resilience for this critical life history stage.

Habitat Use Throughout a Chondrichthyan's Life

<p>Over the last few decades, much effort has been devoted towards evaluating and reducing bycatch in marine fisheries. There has been a particular focus on quantifying the risk to chondrichthyans, primarily because of their relatively high vulnerability to overfishing. A key part of risk assessment is evaluating the distributional overlap of the fish with the fisheries, where fish distribution is influenced by habitat use. I synthesised published observations of habitat use for different life history stages of chondrichthyans and hypothesised the associated catch composition in terms of fish sex, size, and maturity. I then searched for these catch compositions, and thereby locations, using New Zealand research vessel catch data. Results show that some life history stages and habitats for certain species can be identified, whereas others could not. Pupping ground criteria were met for Callorhynchus milii (ELE), Hydrolagus novaezealandiae (GSH), and Hydrolagus bemisi (GSP); nursery ground criteria were met for Callorhynchus milii (ELE), mating ground criteria were met for Callorhynchus milii (ELE), Hydrolagus novaezealandiae (GSH), Hydrolagus bemisi (GSP), and Harriotta raleighana (LCH); lek-like mating criteria were met for Hydrolagus novaezealandiae (GSH). For those life-history stage habitats not found, this may be because these are outside of the coverage of the data set (and likely also commercial fisheries), or because they do not actually exist for some chondrichthyans. On the basis of results, I propose to change the order of species in the New Zealand qualitative (Level 1) risk assessment, and rise the relative risk for Hydrolagus bemisi (GSP), given the species vulnerability of pupping grounds.</p>

Habitat Use Throughout a Chondrichthyan's Life

<p>Over the last few decades, much effort has been devoted towards evaluating and reducing bycatch in marine fisheries. There has been a particular focus on quantifying the risk to chondrichthyans, primarily because of their relatively high vulnerability to overfishing. A key part of risk assessment is evaluating the distributional overlap of the fish with the fisheries, where fish distribution is influenced by habitat use. I synthesised published observations of habitat use for different life history stages of chondrichthyans and hypothesised the associated catch composition in terms of fish sex, size, and maturity. I then searched for these catch compositions, and thereby locations, using New Zealand research vessel catch data. Results show that some life history stages and habitats for certain species can be identified, whereas others could not. Pupping ground criteria were met for Callorhynchus milii (ELE), Hydrolagus novaezealandiae (GSH), and Hydrolagus bemisi (GSP); nursery ground criteria were met for Callorhynchus milii (ELE), mating ground criteria were met for Callorhynchus milii (ELE), Hydrolagus novaezealandiae (GSH), Hydrolagus bemisi (GSP), and Harriotta raleighana (LCH); lek-like mating criteria were met for Hydrolagus novaezealandiae (GSH). For those life-history stage habitats not found, this may be because these are outside of the coverage of the data set (and likely also commercial fisheries), or because they do not actually exist for some chondrichthyans. On the basis of results, I propose to change the order of species in the New Zealand qualitative (Level 1) risk assessment, and rise the relative risk for Hydrolagus bemisi (GSP), given the species vulnerability of pupping grounds.</p>

Impacts of dams on freshwater turtles: a global review to identify conservation solutions

Dams create many impacts on freshwater ecosystems and biodiversity. Freshwater turtles are at direct and indirect risk due to changes caused by damming including the loss of terrestrial and aquatic nesting and feeding habitats, changes to resource availability and reduced dispersal. We reviewed the global scientific literature that evaluated the impact of dams on freshwater turtles, and carried out additional searches of literature published in seventeen languages for studies evaluating actions to mitigate the impact of dams. The search produced 43 published articles documenting dam impacts on 29 freshwater turtle species from seven families (Chelidae, Chelydridae, Emydidae, Geoemydidae, Kinosternidae, Podocnemididae and Trionychidae) in 13 countries. More than a third of studies (41.9%, n = 18) focused on nine North American species of the Emydidae. Few studies were found from Europe and Asia and none from Africa. The number of studies, life-history stage studied and threat status differed significantly between temperate and tropical latitudes. Most studies were from temperate latitudes, where studies focused more on adults and less threatened species compared with tropical latitudes. Studies evaluated dam impacts as barriers and changes to water flow and quality, but no studies were found that assessed turtles and changes to land cover or mercury caused by dams. More than half of the studies (59%, n = 24) suggested actions to help mitigate dam impacts. Yet, only four studies on three temperate and one tropical species documented the effect of interventions (dam removal, flow management, artificial pond maintenance and community-based action). These findings demonstrate a lack of documented evidence evaluating dam impacts on freshwater turtles particularly in tropical regions. This lack of evidence reinforces the importance of strengthening and maintaining robust long-term studies of freshwater turtles needed to develop effective conservation actions for this group of vertebrates.

Analysis of Sr and Ba profiles measured by ultra-high-resolution mass spectrometry LA-ICP-MS in otoliths of juvenile anadromous sockeye salmon Oncorhynchus nerka in the early marine life-history stage as a proxy for fresh to marine water transition

The strontium (Sr) and barium (Ba) profiles in otoliths of juvenile sockeye salmon Oncorhynchus nerka from British Columbia are measured using a Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) system and analyzed. The highest possible measurement resolution (near-daily) was used to assess variability and repeatability of the breakpoint (marine entry) estimates inferred from Sr:Ca and Ba:Ca ratios. Such resolution for the otolith chemical composition (to an accuracy of 2 μm) was reached using the rotating slit, which width was close to the daily circulus width of the otoliths. So, daily or 2-day changes in the elemental composition were recorded during the period of transition to the marine environment. Sr profiles were generally similar among the fish, starting with low values of Sr:Ca in the fresh water and increasing sharply after the marine entry. The Ba:Ca signal was more complex, showing in most cases a dramatic increase immediately before the breakpoint. Besides, multiple peaks in the Ba profiles were recorded prior to the marine transition with a significant difference of their number between fish from different populations. A breakpoint was detectable in the Ba profiles 3–11 µm prior to its appearance in the Sr profiles. The complexity of Ba profiles may cause erroneous estimates of the marine entry date; thus, the Sr signal is a more reliable marker of marine transition for juvenile sockeye.

Short-term elevations in glucocorticoids do not alter telomere lengths: A systematic review and meta-analysis of non-primate vertebrate studies

Background The neuroendocrine stress response allows vertebrates to cope with stressors via the activation of the Hypothalamic-Pituitary-Adrenal (HPA) axis, which ultimately results in the secretion of glucocorticoids (GCs). Glucocorticoids have pleiotropic effects on behavior and physiology, and might influence telomere length dynamics. During a stress event, GCs mobilize energy towards survival mechanisms rather than to telomere maintenance. Additionally, reactive oxygen species produced in response to increased GC levels can damage telomeres, also leading to telomere shortening. In our systematic review and meta-analysis, we tested whether GC levels impact telomere length and if this relationship differs among time frame, life history stage, or stressor type. We hypothesized that elevated GC levels are linked to a decrease in telomere length. Methods We conducted a literature search for studies investigating the relationship between telomere length and GCs in non-human vertebrates using four search engines: Web of Science, Google Scholar, Pubmed and Scopus, last searched on September 27th, 2020. This review identified 31 studies examining the relationship between GCs and telomere length. We pooled the data using Fisher’s Z for 15 of these studies. All quantitative studies underwent a risk of bias assessment. This systematic review study was registered in the Open Science Framework Registry (https://osf.io/rqve6). Results The pooled effect size from fifteen studies and 1066 study organisms shows no relationship between GCs and telomere length (Fisher’s Z = 0.1042, 95% CI = 0.0235; 0.1836). Our meta-analysis synthesizes results from 15 different taxa from the mammalian, avian, amphibian groups. While these results support some previous findings, other studies have found a direct relationship between GCs and telomere dynamics, suggesting underlying mechanisms or concepts that were not taken into account in our analysis. The risk of bias assessment revealed an overall low risk of bias with occasional instances of bias from missing outcome data or bias in the reported result. Conclusion We highlight the need for more targeted experiments to understand how conditions, such as experimental timeframes, stressor(s), and stressor magnitudes can drive a relationship between the neuroendocrine stress response and telomere length.

Plastic responses of survival and fertility following heat stress in pupal and adult Drosophila virilis

The impact of rising global temperatures on survival and reproduction is putting many species at risk of extinction. In particular, it has recently been shown that thermal effects on reproduction, especially limits to male fertility, can underpin species distributions in insects. However, the physiological factors influencing fertility at high temperatures are poorly understood. Key factors that affect somatic thermal tolerance such as hardening, the ability to phenotypically increase thermal tolerance after a mild heat shock, and the differential impact of temperature on different life stages, are largely unexplored for thermal fertility tolerance. Here, we examine the impact of high temperatures on male fertility in the cosmopolitan fruit fly Drosophila virilis. We first determined whether temperature stress at either the pupal or adult life-history stage impacts fertility. We then tested the capacity for heat-hardening to mitigate heat-induced sterility. We found that thermal stress reduces fertility in different ways in pupae and adults. Pupal heat stress delays sexual maturity, whereas males heated as adults can reproduce initially following heat stress, but lose the ability to produce offspring. We also found evidence that while heat-hardening in D. virilis can improve high temperature survival, there is no significant protective impact of this same hardening treatment on fertility. These results suggest that males may be unable to prevent the costs of high temperature stress on fertility through heat-hardening which limits a species’ ability to quickly and effectively reduce fertility loss in the face of short-term high temperature events.