Climate change affects ecological processes and interactions, including parasitism. Because parasites are natural components of ecological systems, as well as agents of outbreak and disease-induced ...mortality, it is important to summarize current knowledge of the sensitivity of parasites to climate and identify how to better predict their responses to it. This need is particularly great in marine systems, where the responses of parasites to climate variables are less well studied than those in other biomes. As examples of climate's influence on parasitism increase, they enable generalizations of expected responses as well as insight into useful study approaches, such as thermal performance curves that compare the vital rates of hosts and parasites when exposed to several temperatures across a gradient. For parasites not killed by rising temperatures, some simple physiological rules, including the tendency of temperature to increase the metabolism of ectotherms and increase oxygen stress on hosts, suggest that parasites' intensity and pathologies might increase. In addition to temperature, climate-induced changes in dissolved oxygen, ocean acidity, salinity, and host and parasite distributions also affect parasitism and disease, but these factors are much less studied. Finally, because parasites are constituents of ecological communities, we must consider indirect and secondary effects stemming from climate-induced changes in host-parasite interactions, which may not be evident if these interactions are studied in isolation.
Information on parasites and disease in marine ecosystems lags behind terrestrial systems, increasing the challenge of predicting responses of marine host-parasite systems to climate change. However, ...here I examine several generalizable aspects and research priorities. First, I advocate that quantification and comparison of host and parasite thermal performance curves is a smart approach to improve predictions of temperature effects on disease. Marine invertebrate species are ectothermic and should be highly conducive to this approach given their generally short generation times. Second, in marine systems, shallow subtidal and intertidal areas will experience the biggest temperature swings and thus likely see the most changes to host-parasite dynamics. Third, for some responses like parasite intensity, as long as the lethal limit of the parasite is not crossed, on average, there may be a biological basis to expect temperature-dependent intensification of impacts on hosts. Fourth, because secondary mortality effects and indirect effects of parasites can be very important, we need to study temperature effects on host-parasite dynamics in a community context to truly know their bottom line effects. This includes examining climate-influenced effects of parasites on ecosystem engineers given their pivotal role in communities. Finally, other global change factors, especially hypoxia, salinity, and ocean acidity, covary with temperature change and need to be considered and evaluated when possible for their contributing effects on host-parasite systems. Climate change-disease interactions in nearshore marine environments are complex; however, generalities are possible and continued research, especially in the areas outlined here, will improve our understanding.
Abstract
Ecosystem engineers (EEs) strongly influence ecosystems by affecting the abiotic properties of a system to which many biota respond. EEs can, thus, be pivotal species in restoration by ...helping to move systems toward desired states much faster and more efficiently than direct human intervention on the abiotic state.
For EEs to play a central, purposeful role in restoration, it is important to identify guiding principles about how the EEs may best be selected and incorporated.
I discuss three important aspects to determine (a) where the utility for EEs is high; (b) where EEs can most easily establish, are easy to handle and scaling‐up their use is possible; and (c) how to recognize and value multiple, coupled and trait‐dependent engineering functions of EEs.
Understanding these aspects of EEs should help guide purposeful and efficient choices in our approach to restoration.
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Resumen
Los ingenieros ecosistémicos (EEs) influyen fuertemente los ecosistemas, afectando las propiedades abióticas de éstos, a los cuales responde la biota. De este modo, los EEs pueden ser especies esenciales en la restauración, ayudando a mover los sistemas hacia estados deseados más rápido y eficiente, que la intervención humana directa sobre el estado abiótico.
Para que los EEs desempeñen un papel central y útil en la restauración, es importante identificar los principales criterios sobre cómo se puede elegir e incorporar mejor los EEs.
Discuto tres aspectos importantes para determinar (1) dónde la utilidad de los EEs es alta, (2) dónde los EEs pueden establecerse mas fácilmente, son fáciles de manipular y es posible ampliar su uso, y (3) cómo reconocer y valorar las múltiples, acopladas, y los rasgos‐dependiente de las funciones ingenieras de los EEs
Entender estos aspectos de los EEs debería ayudar a orientar hacia la toma de mejores decisiones en nuestro enfoque a la restauración.
Perros domésticos son reportados forrajeando sobre el chanchito de mar Emerita analoga en la playa Curiñanco, Valdivia, Chile. Consumir estos crustáceos representa un potencial riesgo para la salud ...de ellos, ya que E. analoga alberga larvas del acantocéfalo Profilicollis altmani, el cual usa a las aves como hospedador definitivo, pero que también parasita a mamíferos marinos, terrestres e incluso a humanos. Finalmente, los perros no sólo interrumpen el forrajeo de las aves, sino que ahora compiten por el mismo recurso.
Despite knowledge on invasive species’ predatory effects, we know little of their influence as prey. Non‐native prey should have a neutral to positive effect on native predators by supplementing the ...prey base. However, if non‐native prey displace native prey, then an invader's net influence should depend on both its abundance and value relative to native prey. We conducted a meta‐analysis to quantify the effect of non‐native prey on native predator populations. Relative to native prey, non‐native prey similarly or negatively affect native predators, but only when studies employed a substitutive design that examined the effects of each prey species in isolation from other prey. When native predators had access to non‐native and native prey simultaneously, predator abundance increased significantly relative to pre‐invasion abundance. Although non‐native prey may have a lower per capita value than native prey, they seem to benefit native predators by serving as a supplemental prey resource.
A global synthesis of predation on bivalves Meira, Alexandra; Byers, James E.; Sousa, Ronaldo
Biological reviews of the Cambridge Philosophical Society,
June 2024, 2024-Jun, 2024-06-00, 20240601, Letnik:
99, Številka:
3
Journal Article
Recenzirano
ABSTRACT
Predation is a dominant structuring force in ecological communities. In aquatic environments, predation on bivalves has long been an important focal interaction for ecological study because ...bivalves have central roles as ecosystem engineers, basal components of food webs, and commercial commodities. Studies of bivalves are common, not only because of bivalves' central roles, but also due to the relative ease of studying predatory effects on this taxonomic group. To understand patterns in the interactions of bivalves and their predators we synthesised data from 52 years of peer‐reviewed studies on bivalve predation. Using a systematic search, we compiled 1334 studies from 75 countries, comprising 61 bivalve families (N = 2259), dominated by Mytilidae (29% of bivalves), Veneridae (14%), Ostreidae (8%), Unionidae (7%), and Dreissenidae and Tellinidae (6% each). A total of 2036 predators were studied, with crustaceans the most studied predator group (34% of predators), followed by fishes (24%), molluscs (17%), echinoderms (10%) and birds (6%). The majority of studies (86%) were conducted in marine systems, in part driven by the high commercial value of marine bivalves. Studies in freshwater ecosystems were dominated by non‐native bivalves and non‐native predator species, which probably reflects the important role of biological invasions affecting freshwater biodiversity. In fact, while 81% of the studied marine bivalve species were native, only 50% of the freshwater species were native to the system.
In terms of approach, most studies used predation trials, visual analysis of digested contents and exclusion experiments to assess the effects of predation. These studies reflect that many factors influence bivalve predation depending on the species studied, including (i) species traits (e.g. behaviour, morphology, defence mechanisms), (ii) other biotic interactions (e.g. presence of competitors, parasites or diseases), and (iii) environmental context (e.g. temperature, current velocity, beach exposure, habitat complexity). There is a lack of research on the effects of bivalve predation at the population and community and ecosystem levels (only 7% and 0.5% of studies respectively examined impacts at these levels). At the population level, the available studies demonstrate that predation can decrease bivalve density through consumption or the reduction of recruitment. At the community and ecosystem level, predation can trigger effects that cascade through trophic levels or effects that alter the ecological functions bivalves perform. Given the conservation and commercial importance of many bivalve species, studies of predation should be pursued in the context of global change, particularly climate change, acidification and biological invasions.
The desire to stabilize coastlines has led to widespread use of hard armoring infrastructure across the globe; however, ecologists and coastal managers have increasingly documented the deleterious ...effects of armoring on ecological communities. Although many studies have assessed economic and landscape correlates of armoring, few studies incorporate race as a predictor of armoring. Race may be an important force structuring the placement of armoring due to the long history of Black land loss in the US Southeast. Here, we assessed the distribution of armoring in the US state of South Carolina with respect to demographic and housing characteristics using a high spatial resolution data set and a combination of spatial statistics and generalized linear mixed models. We found clusters of high armoring counts in the more urbanized Beaufort and Charleston counties, with these clusters frequently occurring in large-scale, planned communities. We found a positive correlation between armoring count and the percentage of White residents, with the number of armoring structures predicted to increase from 1.61 to 7.77 between census block groups (CBGs) that are 0 to 100% White. Armoring count and the percentage of homeowners also showed a positive correlation with a similar magnitude of effect, with the number of armoring structures predicted to increase from 1.14 to 8.97 between CBGs that are 0 to 100% homeowners. These results highlight that racial composition and homeownership are strong predictors of armoring count on private, personal property, which provides critical context for how these structures are distributed and underscores that socioeconomic factors can control where their associated environmental impacts may be concentrated.
Homeowners in coastal environments often augment their access to estuarine ecosystems by building private docks on their personal property. Despite the commonality of docks, particularly in the ...Southeastern United States, few works have investigated their historical development, their distribution across the landscape, or the environmental justice dimensions of this distribution. In this study, we used historic aerial photography to track the abundance and size of docks across six South Carolina counties from the 1950s to 2016. Across our roughly 60-year study period, dock abundance grew by two orders of magnitude, mean length of newly constructed docks doubled, and the cumulative length of docks ballooned from 34 to 560 km. Additionally, we drew on census data interpolated into consistent 2010 tract boundaries to analyze the racial and economic distribution of docks in 1994, 1999, 2011, and 2016. Racial composition, measured as the percentage of a tract's population that was White, positively correlated with dock abundance in each year. Median household income and dock abundance were only correlated in 2011. Taken together, these metrics indicate the growing desire for direct estuary access, however, that access does not appear to be equally spread across racial groups. Because docks enhance estuarine access and demarcate private property, our study provides longitudinal insights into environmental justice concerns related to disparate private property ownership. We found a persistent correlation between the racial characteristics of an area and dock abundance, strongly indicating that White South Carolinians have had disproportionately greater private water access for the past two decades.
Host–parasite systems have intricately coupled life cycles, but each interactor can respond differently to changes in environmental variables like temperature. Although vital to predicting how ...parasitism will respond to climate change, thermal responses of both host and parasite in key traits affecting infection dynamics have rarely been quantified. Through temperature-controlled experiments on an ectothermic host–parasite system, we demonstrate an offset in the thermal optima for survival of infected and uninfected hosts and parasite production. We combine experimentally derived thermal performance curves with field data on seasonal host abundance and parasite prevalence to parameterize an epidemiological model and forecast the dynamical responses to plausible future climate-warming scenarios. In warming scenarios within the coastal southeastern United States, the model predicts sharp declines in parasite prevalence, with local parasite extinction occurring with as little as 2 °C warming. The northern portion of the parasite’s current range could experience local increases in transmission, but assuming no thermal adaptation of the parasite, we find no evidence that the parasite will expand its range northward under warming. This work exemplifies that some host populations may experience reduced parasitism in a warming world and highlights the need to measure host and parasite thermal performance to predict infection responses to climate change.
Scientific and societal unknowns make it difficult to predict how global environmental changes such as climate change and biological invasions will affect ecological systems. In the long term, these ...changes may have interacting effects and compound the uncertainty associated with each individual driver. Nonetheless, invasive species are likely to respond in ways that should be qualitatively predictable, and some of these responses will be distinct from those of native counterparts. We used the stages of invasion known as the "invasion pathway" to identify 5 nonexclusive consequences of climate change for invasive species: (1) altered transport and introduction mechanisms, (2) establishment of new invasive species, (3) altered impact of existing invasive species, (4) altered distribution of existing invasive species, and (5) altered effectiveness of control strategies. We then used these consequences to identify testable hypotheses about the responses of invasive species to climate change and provide suggestions for invasive-species management plans. The 5 consequences also emphasize the need for enhanced environmental monitoring and expanded coordination among entities involved in invasive-species management.