scholarly journals Production of mobile invertebrate communities on shallow reefs from temperate to tropical seas

2020 ◽  
Vol 287 (1941) ◽  
pp. 20201798
Author(s):  
K. M. Fraser ◽  
J. S. Lefcheck ◽  
S. D. Ling ◽  
C. Mellin ◽  
R. D. Stuart-Smith ◽  
...  
Keyword(s):  
Primary Productivity ◽  
Human Impacts ◽  
Anthropogenic Impacts ◽  
Selection Procedure ◽  
Marine Ecosystems ◽  
Environmental Drivers ◽  
Kelp Forests ◽  
Food Web Structure ◽  
Continental Scale ◽  
Biogenic Habitat

Primary productivity of marine ecosystems is largely driven by broad gradients in environmental and ecological properties. By contrast, secondary productivity tends to be more variable, influenced by bottom-up (resource-driven) and top-down (predatory) processes, other environmental drivers, and mediation by the physical structure of habitats. Here, we use a continental-scale dataset on small mobile invertebrates (epifauna), common on surfaces in all marine ecosystems, to test influences of potential drivers of temperature-standardized secondary production across a large biogeographic range. We found epifaunal production to be remarkably consistent along a temperate to tropical Australian latitudinal gradient of 28.6°, spanning kelp forests to coral reefs (approx. 3500 km). Using a model selection procedure, epifaunal production was primarily related to biogenic habitat group, which explained up to 45% of total variability. Production was otherwise invariant to predictors capturing primary productivity, the local biomass of fishes (proxy for predation pressure), and environmental, geographical, and human impacts. Highly predictable levels of epifaunal productivity associated with distinct habitat groups across continental scales should allow accurate modelling of the contributions of these ubiquitous invertebrates to coastal food webs, thus improving understanding of likely changes to food web structure with ocean warming and other anthropogenic impacts on marine ecosystems.

scholarly journals A human impact metric for coastal ecosystems with application to seagrass beds in Atlantic Canada

2018 ◽  
Author(s):  
Grace E.P. Murphy ◽  
Melisa Wong ◽  
Heike K. Lotze
Keyword(s):  
Human Impact ◽  
Human Impacts ◽  
Anthropogenic Impacts ◽  
Coastal Ecosystems ◽  
Atlantic Canada ◽  
Seagrass Beds ◽  
General Application ◽  
Coastal Bays ◽  
Biogenic Habitat ◽  
Seagrass Ecosystems

AbstractCoastal biogenic habitats are particularly vulnerable to cumulative human impacts from both terrestrial and marine realms. Yet the broad spatial scale used in current global or regional approaches of quantifying multiple anthropogenic stressors are not relevant to the local or bay-wide scales affecting most coastal biogenic habitats. To fill this gap, we developed a standardized human impact metric to quantify the magnitude of anthropogenic impacts to coastal ecosystems more broadly, and biogenic habitats in particular. We applied this metric to 180 seagrass beds (Zostera marina), an important biogenic habitat prioritized for marine protection, across Atlantic Canada. Our impact metric includes five bay-scale and four local-scale terrestrial and marine-based impacts. Results show that seagrass beds and coastal bays in Atlantic Canada exist across a wide gradient of human impacts. Considerable differences in the range and intensity of impacts within and between regions provide insight into where coastal bays and seagrass ecosystems are expected to be most and least affected by individual or cumulative human threats. We discuss implications for management and conservation planning, and the general application of our impact metric to other coastal regions and habitats in Canada and beyond.

scholarly journals Long-term changes in kelp forests in an inner basin of the Salish Sea

2020 ◽  
Author(s):  
Helen D. Berry ◽  
Thomas F. Mumford ◽  
Bart Christiaen ◽  
Pete Dowty ◽  
Max Calloway ◽  
...  
Keyword(s):  
Human Impacts ◽  
Recent Observation ◽  
Puget Sound ◽  
Kelp Forests ◽  
Limited Data ◽  
Biogenic Habitat ◽  
Conservation Actions ◽  
Almost All ◽  
Insight Into

AbstractUnderstanding the historical extent of biogenic habitats can provide insight into the nature of human impacts and inform restoration and conservation actions. Kelp forests form an important biogenic habitat that responds to natural and human drivers. Global concerns exist about threats to kelp forests, yet long term information is limited and research suggests that trends are geographically distinct. We examined distribution of the bull kelp Nereocystis luetkeana over 145 years in South Puget Sound (SPS), a semi-protected inner basin in a fjord estuary complex in the northeast Pacific Ocean. We synthesized 48 historical and modern Nereocystis surveys and examined presence/absence within 1-km shoreline segments along 452 km of shoreline. Over the last 145 years, Nereocystis has been documented in 26% of the shoreline segments. Its extent decreased 62% basin-wide between the 1870s and 2017, with extreme losses in the two out of three sub-basins (96% in Central and 83% in West). In recent years, almost all Nereocystis occurred in the East sub-basin. In the majority of segments where Nereocystis disappeared, the most recent observation was 4 decades ago, or earlier. Multiple natural and human factors that are known to impact kelp could have contributed to observed patterns, but limited data exist at the spatial and temporal scale of this study. In some areas, recent environmental conditions approached thresholds associated with decreased kelp performance. Longstanding Nereocystis losses occurred exclusively in areas with relatively low current velocities. Remaining Nereocystis predominantly occurred in areas where circulation is stronger. Exceptions to this pattern demonstrate that additional factors outside the scope of this study contributed to trajectories of Nereocystis persistence or loss.

scholarly journals Sensitivity of gross primary productivity to climatic drivers during the summer drought of 2018 in Europe

2020 ◽  
Vol 375 (1810) ◽  
pp. 20190747 ◽  
Author(s):  
Zheng Fu ◽  
Philippe Ciais ◽  
Ana Bastos ◽  
Paul C. Stoy ◽  
Hui Yang ◽  
...  
Keyword(s):  
Primary Productivity ◽  
Vapour Pressure Deficit ◽  
Photosynthetic Photon Flux Density ◽  
Gross Primary Productivity ◽  
Environmental Drivers ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Severe Drought ◽  
Summer Drought ◽  
Continental Scale

In summer 2018, Europe experienced a record drought, but it remains unknown how the drought affected ecosystem carbon dynamics. Using observations from 34 eddy covariance sites in different biomes across Europe, we studied the sensitivity of gross primary productivity (GPP) to environmental drivers during the summer drought of 2018 versus the reference summer of 2016. We found a greater drought-induced decline of summer GPP in grasslands (−38%) than in forests (−10%), which coincided with reduced evapotranspiration and soil water content (SWC). As compared to the ‘normal year’ of 2016, GPP in different ecosystems exhibited more negative sensitivity to summer air temperature (Ta) but stronger positive sensitivity to SWC during summer drought in 2018, that is, a stronger reduction of GPP with soil moisture deficit. We found larger negative effects of Ta and vapour pressure deficit (VPD) but a lower positive effect of photosynthetic photon flux density on GPP in 2018 compared to 2016, which contributed to reduced summer GPP in 2018. Our results demonstrate that high temperature-induced increases in VPD and decreases in SWC aggravated drought impacts on GPP. This article is part of the theme issue ‘Impacts of the 2018 severe drought and heatwave in Europe: from site to continental scale’.

Environmental drivers of cladoceran assemblages at a continental scale: A synthesis of Alaskan and Canadian datasets

2021 ◽  
Vol 66 (5) ◽  
pp. 949-967
Author(s):  
Andrew L. Labaj ◽  
Adam Jeziorski ◽  
Joshua Kurek ◽  
Joseph R. Bennett ◽  
Brian F. Cumming ◽  
...  
Keyword(s):  
Environmental Drivers ◽  
Continental Scale

scholarly journals Trophic control of cryptic coralline algal diversity

2019 ◽  
Vol 116 (30) ◽  
pp. 15080-15085 ◽  
Author(s):  
Katharine R. Hind ◽  
Samuel Starko ◽  
Jenn M. Burt ◽  
Matthew A. Lemay ◽  
Anne K. Salomon ◽  
...  
Keyword(s):  
Algal Species ◽  
Trophic Dynamics ◽  
Kelp Forests ◽  
Negative Consequences ◽  
Food Web Structure ◽  
Nearshore Ecosystems ◽  
Keystone Predation ◽  
Ecological Patterns ◽  
Ecosystem Level ◽  
Algal Assemblages

Understanding how trophic dynamics drive variation in biodiversity is essential for predicting the outcomes of trophic downgrading across the world’s ecosystems. However, assessing the biodiversity of morphologically cryptic lineages can be problematic, yet may be crucial to understanding ecological patterns. Shifts in keystone predation that favor increases in herbivore abundance tend to have negative consequences for the biodiversity of primary producers. However, in nearshore ecosystems, coralline algal cover increases when herbivory is intense, suggesting that corallines may uniquely benefit from trophic downgrading. Because many coralline algal species are morphologically cryptic and their diversity has been globally underestimated, increasing the resolution at which we distinguish species could dramatically alter our conclusions about the consequences of trophic dynamics for this group. In this study, we used DNA barcoding to compare the diversity and composition of cryptic coralline algal assemblages at sites that differ in urchin biomass and keystone predation by sea otters. We show that while coralline cover is greater in urchin-dominated sites (or “barrens”), which are subject to intense grazing, coralline assemblages in these urchin barrens are significantly less diverse than in kelp forests and are dominated by only 1 or 2 species. These findings clarify how food web structure relates to coralline community composition and reconcile patterns of total coralline cover with the widely documented pattern that keystone predation promotes biodiversity. Shifts in coralline diversity and distribution associated with transitions from kelp forests to urchin barrens could have ecosystem-level effects that would be missed by ignoring cryptic species’ identities.

Anthropogenic impacts on marine ecosystems in Antarctica

2011 ◽  
Vol 1223 (1) ◽  
pp. 82-107 ◽  
Author(s):  
Richard B. Aronson ◽  
Sven Thatje ◽  
James B. McClintock ◽  
Kevin A. Hughes
Keyword(s):  
Anthropogenic Impacts ◽  
Marine Ecosystems

scholarly journals Technical note: Dynamic INtegrated Gap-filling and partitioning for OzFlux (DINGO)

2017 ◽  
Vol 14 (6) ◽  
pp. 1457-1460 ◽  
Author(s):  
Jason Beringer ◽  
Ian McHugh ◽  
Lindsay B. Hutley ◽  
Peter Isaac ◽  
Natascha Kljun
Keyword(s):  
Primary Productivity ◽  
Active Sites ◽  
Ecosystem Respiration ◽  
Technical Note ◽  
Gross Primary Productivity ◽  
Quality Data ◽  
Gap Filling ◽  
Continental Scale ◽  
Flux Data ◽  
Processing Pathways

Abstract. Standardised, quality-controlled and robust data from flux networks underpin the understanding of ecosystem processes and tools necessary to support the management of natural resources, including water, carbon and nutrients for environmental and production benefits. The Australian regional flux network (OzFlux) currently has 23 active sites and aims to provide a continental-scale national research facility to monitor and assess Australia's terrestrial biosphere and climate for improved predictions. Given the need for standardised and effective data processing of flux data, we have developed a software suite, called the Dynamic INtegrated Gap-filling and partitioning for OzFlux (DINGO), that enables gap-filling and partitioning of the primary fluxes into ecosystem respiration (Fre) and gross primary productivity (GPP) and subsequently provides diagnostics and results. We outline the processing pathways and methodologies that are applied in DINGO (v13) to OzFlux data, including (1) gap-filling of meteorological and other drivers; (2) gap-filling of fluxes using artificial neural networks; (3) the u* threshold determination; (4) partitioning into ecosystem respiration and gross primary productivity; (5) random, model and u* uncertainties; and (6) diagnostic, footprint calculation, summary and results outputs. DINGO was developed for Australian data, but the framework is applicable to any flux data or regional network. Quality data from robust systems like DINGO ensure the utility and uptake of the flux data and facilitates synergies between flux, remote sensing and modelling.

Human Impacts on Ancient Marine Ecosystems

2020 ◽  
pp. 5334-5336
Author(s):  
Torben C. Rick ◽  
Jon M. Erlandson
Keyword(s):  
Human Impacts ◽  
Marine Ecosystems
Sign in / Sign up

Export Citation Format

Share Document