An official website of the United States government
Foundation species, which help maintain habitat and ecosystem functioning, are declining due to anthropogenic impacts. Within the rocky intertidal ecosystem, studies have investigated the effects of foundation species on community structure and some resource fluxes; however, how intertidal foundation species loss will affect multiple facets of ecosystem functioning in concert remains unknown. We studied the direct and indirect effects of foundation species loss of mussels Mytilus californianus and surfgrass Phyllospadix spp. on community structure, fluxes (light, temperature, dissolved oxygen [DO], dissolved inorganic nutrients, pH T ), and ecosystem metabolism (net ecosystem calcification [NEC] and net ecosystem production [NEP]) in central Oregon using in situ tide pool manipulations. Surfgrass loss increased microalgae cover, increased average maximum light by 142% and average maximum temperature by 3.8°C, increased DO and pH T values, and indirectly increased NEP and NEC via increased maximum temperature and pH T respectively. Mussel loss increased microalgae cover, increased average maximum light by 5.8% and average maximum temperature by 1.3°C, increased DO and pH T values, and indirectly increased NEP via increased producer cover. Shifts in baseline nutrient concentrations and temperature values from coastal upwelling influenced ecosystem metabolism in pools with intact foundation species. Our results indicate that as communities respond to foundation species loss, ecosystem functioning depends on the dominant community present and biologically or physically driven shifts in biogeochemistry. This study highlights the importance of the connection between community and ecosystem ecology in understanding the magnitude of changes occurring with anthropogenically-driven intertidal foundation species loss.
more »
« less
North-East Pacific: Interactions on intertidal hard substrata and alteration by human impacts
The flora and fauna of the rocky intertidal zone are among the most biologically diverse on the planet – not in terms of species richness, but of the diversity and density of higher taxonomic categories. All of the major animal phyla can be found in the rocky intertidal, sometimes with representatives of each inhabiting a single rock or boulder. In addition to this phylogenetic diversity, the rocky intertidal may be one of the most ancient of habitats because it is a necessary and continual result of celestial mechanics set in motion prior to the diversification of life. When advising readers to ‘. . . look from the tide pool to the stars and then back to the tide pool again’, Steinbeck and Ricketts (1951) seemed to underline this point while advocating for a holistic approach to ecological research. A few years earlier, Ricketts and Calvin set out to comprehensively document what was then known about the ecology of the north-eastern Pacific (NEP) rocky intertidal in their classic book, Between Pacific Tides (Ricketts et al., 1985). Since the first edition of Between Pacific Tides (1939), the NEP has become widely recognised as an ideal natural laboratory for experimental ecologists and as a platform for more observationally focussed ecologists seeking to understand macroecological and biogeographical patterns. It is, of course, outside the scope of this chapter to attempt a comprehensive review of this extensive research. Rather, we focus on a couple of broad topics that are central to our current understanding of fundamental ecological, evolutionary and conservation topics that have benefitted from NEP rocky intertidal case studies. The first half of the chapter deals with recent work on the biotic and abiotic factors influencing patterns of range wide abundance and distribution of species, and how such patterns are being affected by human impacts. The second half reviews the latest research on the role of direct and indirect human impacts on topdown and bottom-up control of rocky intertidal community structure and functioning.
more »
« less
- PAR ID:
- 10154636
- Date Published:
- Journal Name:
- Interactions in the Marine Benthos: Global Patterns and Processes
- Page Range / eLocation ID:
- 237-259
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Abstract Marine protected areas (MPAs) have gained attention as a conservation tool for enhancing ecosystem resilience to climate change. However, empirical evidence explicitly linking MPAs to enhanced ecological resilience is limited and mixed. To better understand whether MPAs can buffer climate impacts, we tested the resistance and recovery of marine communities to the 2014–2016 Northeast Pacific heatwave in the largest scientifically designed MPA network in the world off the coast of California, United States. The network consists of 124 MPAs (48 no‐take state marine reserves, and 76 partial‐take or special regulation conservation areas) implemented at different times, with full implementation completed in 2012. We compared fish, benthic invertebrate, and macroalgal community structure inside and outside of 13 no‐take MPAs across rocky intertidal, kelp forest, shallow reef, and deep reef nearshore habitats in California's Central Coast region from 2007 to 2020. We also explored whether MPA features, including age, size, depth, proportion rock, historic fishing pressure, habitat diversity and richness, connectivity, and fish biomass response ratios (proxy for ecological performance), conferred climate resilience for kelp forest and rocky intertidal habitats spanning 28 MPAs across the full network. Ecological communities dramatically shifted due to the marine heatwave across all four nearshore habitats, and MPAs did not facilitate habitat‐wide resistance or recovery. Only in protected rocky intertidal habitats did community structure significantly resist marine heatwave impacts. Community shifts were associated with a pronounced decline in the relative proportion of cold water species and an increase in warm water species. MPA features did not explain resistance or recovery to the marine heatwave. Collectively, our findings suggest that MPAs have limited ability to mitigate the impacts of marine heatwaves on community structure. Given that mechanisms of resilience to climate perturbations are complex, there is a clear need to expand assessments of ecosystem‐wide consequences resulting from acute climate‐driven perturbations, and the potential role of regulatory protection in mitigating community structure changes.more » « less
-
Abstract Intertidal animals deal with physical gradients daily that create stressful conditions across the shore. These physical gradients influence the physiological performance of organisms, requiring responses that may differ with height on the shore. We examined the respiratory response to aerial exposure in the invasive Asian shore crabHemigrapsus sanguineusduring periods of low tide emersion using two field experiments. The first experiment simultaneously measured respiration of individuals collected from different heights on the shore, which had therefore been emersed for different lengths of time. The second experiment measured respiration of individuals collected at different times from the same tidal height. Respiration rates of crabs in both experiments increased immediately after emersion, nearly doubling by and peaking at ~ 1.5 h of aerial exposure, before decreasing again over the next 1.5 h. These results suggest that the energetic cost of low tide exposure is greatest shortly after emersion during the first half of the typical low tide period, but then decreases thereafter. These respiration patterns facilitate the broad intertidal distribution of this species on rocky shores throughout its range.more » « less
-
Paiva, Vitor_Hugo Rodrigues (Ed.)A powerful way to predict how ecological communities will respond to future climate change is to test how they have responded to the climate of the past. We used climate oscillations including the Pacific Decadal Oscillation (PDO), North Pacific Gyre Oscillation, and El Niño Southern Oscillation (ENSO) and variation in upwelling, air temperature, and sea temperatures to test the sensitivity of nearshore rocky intertidal communities to climate variability. Prior research shows that multiple ecological processes of key taxa (growth, recruitment, and physiology) were sensitive to environmental variation during this time frame. We also investigated the effect of the concurrent sea star wasting disease outbreak in 2013–2014. We surveyed nearly 150 taxa from 11 rocky intertidal sites in Oregon and northern California annually for up to 14-years (2006–2020) to test if community structure (i.e., the abundance of functional groups) and diversity were sensitive to past environmental variation. We found little to no evidence that these communities were sensitive to annual variation in any of the environmental measures, and that each metric was associated with < 8.6% of yearly variation in community structure. Only the years elapsed since the outbreak of sea star wasting disease had a substantial effect on community structure, but in the mid-zone only where spatially dominant mussels are a main prey of the keystone predator sea star,Pisaster ochraceus. We conclude that the established sensitivity of multiple ecological processes to annual fluctuations in climate has not yet scaled up to influence community structure. Hence, the rocky intertidal system along this coastline appears resistant to the range of oceanic climate fluctuations that occurred during the study. However, given ongoing intensification of climate change and increasing frequencies of extreme events, future responses to climate change seem likely.more » « less
-
ABSTRACT AimSurveying the demography of populations near species range edges may indicate their vulnerability to range contractions or local extinction as the climate changes. In the rocky intertidal, not only are latitudinal ranges constricted by thermal stress, but tides also create zonation or a ‘vertical range’ driven by sharp environmental gradients. By investigating demographics along the latitudinal and vertical ranges simultaneously, we can investigate whether populations may be vulnerable to a changing climate. LocationRocky intertidal habitats along west coast of the United States. TaxaOchre sea starPisaster ochraceus, six‐armed sea starLeptasteriasspp., emarginate whelks(Nucella ostrina and N. emarginata) and channeled whelkN. canaliculata. MethodsIn 2018, we surveyed the demographics of the taxa above at 33 sites spanning > 11° latitude from central Oregon to southern California, near the southern range limits of each taxon. We counted and sized individuals from the high to low intertidal zone. To understand how environmental stress changed with latitude, we evaluated intertidal temperaturesin situ, as well as tidal extremes, tidal amplitude and wave exposure using offshore buoys. ResultsFor all taxa, population density, the relative proportion of smaller individuals (except for emarginate whelks) and the upper vertical limits on the shore declined from north to south as temperatures increased and high tide height, tidal amplitude and wave heights decreased. In addition, smaller individualLeptasteriasspp. generally inhabited lower shore levels while smaller individual emarginate whelks inhabited higher shore levels coastwide. ForN. canaliculata, smaller animals were higher on shore northward, but lower on shore southward. Main ConclusionsWhile this study is a snapshot in time and cannot assess impacts of climate change, our surveys suggest environmentally‐related demographic limitation toward southern range limits and demographically vulnerable southern populations. Therefore, a warming climate may cause local extinctions or range contractions near southern limits.more » « less
- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.1017/9781108235792.011
