Effects of urban eutrophication on pelagic habitat capacity in the Southern California Bight

Frieder, Christina A.; Kessouri, Fayçal; Ho, Minna; Sutula, Martha; Bianchi, Daniele; McWilliams, James C.; Deutsch, Curtis; Howard, Evan M.

doi:10.22541/essoar.167870388.82984110/v1

Cited by 2 publications

(1 citation statement)

References 57 publications

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“…Despite discussions on the perceived global increase in algal blooms attributable to intensified monitoring and emerging bloom impacts, these blooms are increasing worldwide as highlighted from satellite images by Dai et al [ 3 ], and thus they are posing various concerns for the local ecology and global climate. Blooms are highly destructive and persistent [ 4 , 5 ], causing various ecological catastrophes, such as the eduction of vegetated communities, widespread sponge mortality and loss of marine habitat geomorphological structure [ 6 ] due to, for instance, habitat calcification [ 7 ].…”

Section: Introductionmentioning

confidence: 99%

Algal Bloom Ties: Spreading Network Inference and Extreme Eco-Environmental Feedback

Wang

Galbraith

Convertino

2023

Entropy

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Coastal marine ecosystems worldwide are increasingly affected by tide alterations and anthropogenic disturbances affecting the water quality and leading to frequent algal blooms. Increased bloom persistence is a serious threat due to the long-lasting impacts on ecological processes and services, such as carbon cycling and sequestration. The exploration of eco-environmental feedback and algal bloom patterns remains challenging and poorly investigated, mostly due to the paucity of data and lack of model-free approaches to infer universal bloom dynamics. Florida Bay, taken as an epitome for biodiversity and blooms, has long experienced algal blooms in its central and western regions, and, in 2006, an unprecedented bloom occurred in the eastern habitats rich in corals and vulnerable habitats. With global aims, we analyze the occurrence of blooms in Florida Bay from three perspectives: (1) the spatial spreading networks of chlorophyll-a (CHLa) that pinpoint the source and unbalanced habitats; (2) the fluctuations of water quality factors pre- and post-bloom outbreaks to assess the environmental impacts of ecological imbalances and target the prevention and control of algal blooms; and (3) the topological co-evolution of biogeochemical and spreading networks to quantify ecosystem stability and the likelihood of ecological shifts toward endemic blooms in the long term. Here, we propose the transfer entropy (TE) difference to infer salient dynamical inter actions between the spatial areas and biogeochemical factors (ecosystem connectome) underpinning bloom emergence and spread as well as environmental effects. A Pareto principle, defining the top 20% of areal interactions, is found to identify bloom spreading and the salient eco-environmental interactions of CHLa associated with endemic and epidemic regimes. We quantify the spatial dynamics of algal blooms and, thus, obtain areas in critical need for ecological monitoring and potential bloom control. The results show that algal blooms are increasingly persistent over space with long-term negative effects on water quality factors, in particular, about how blooms affect temperature locally. A dichotomy is reported between spatial ecological corridors of spreading and biogeochemical networks as well as divergence from the optimal eco-organization: randomization of the former due to nutrient overload and temperature increase leads to scale-free CHLa spreading and extreme outbreaks a posteriori. Subsequently, the occurrence of blooms increases bloom persistence, turbidity and salinity with potentially strong ecological effects on highly biodiverse and vulnerable habitats, such as tidal flats, salt-marshes and mangroves. The probabilistic distribution of CHLa is found to be indicative of endemic and epidemic regimes, where the former sets the system to higher energy dissipation, larger instability and lower predictability. Algal blooms are important ecosystem regulators of nutrient cycles; however, chlorophyll-a outbreaks cause vast ecosystem impacts, such as aquatic species mortality and carbon flux alteration due to their effects on water turbidity, nutrient cycling (nitrogen and phosphorus in particular), salinity and temperature. Beyond compromising the local water quality, other socio-ecological services are also compromised at large scales, including carbon sequestration, which affects climate regulation from local to global environments. Yet, ecological assessment models, such as the one presented, inferring bloom regions and their stability to pinpoint risks, are in need of application in aquatic ecosystems, such as subtropical and tropical bays, to assess optimal preventive controls.

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Section: Introductionmentioning

confidence: 99%

Algal Bloom Ties: Spreading Network Inference and Extreme Eco-Environmental Feedback

Wang

Galbraith

Convertino

2023

Entropy

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Extremes and Short‐Term Fluctuations in Coastal Ocean Acidification and Hypoxia

Damien,

Bianchi,

Kessouri

et al. 2024

JGR Oceans

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In Eastern boundary upwelling systems, such as the California Current System (CCS), seasonal upwelling brings low oxygen and low pH waters to the continental shelf, causing ocean acidification and hypoxia (OAH). The location, frequency, and intensity of OAH events is influenced by a combination of large‐scale climatic trends, seasonal changes, small‐scale circulation, and local human activities. Here, we use results from two 20‐year long submesoscale‐resolving simulations of the Northern and Southern U.S. West Coast (USWC) for the 1997–2017 period, to describe the characteristics and drivers of OAH events. These simulations reveal the emergence of hotspots in which seasonal declines in oxygen and pH are accompanied by localized short‐term extremes in OAH. While OAH hotspots show substantial seasonal variability, significant intra‐seasonal fluctuations occur, reflecting the interaction between low‐ and high‐frequency forcings that shape OAH events. The mechanisms behind the seasonal decreases in pH and oxygen vary along the USWC. While remineralization remains the dominant force causing these declines throughout the coast, physical transport partially offsets these effects in Southern and Central California, but contributes to seasonal oxygen loss and acidification on the Northern Coast. Critically, the seasonal decline is not sufficient to predict the occurrence and duration of OAH extremes. Locally enhanced biogeochemical rates, including shallow benthic remineralization and rapid wind‐driven transport, shape the spatial and temporal patterns of coastal OAH.

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Effects of urban eutrophication on pelagic habitat capacity in the Southern California Bight

Cited by 2 publications

References 57 publications

Algal Bloom Ties: Spreading Network Inference and Extreme Eco-Environmental Feedback

Algal Bloom Ties: Spreading Network Inference and Extreme Eco-Environmental Feedback

Extremes and Short‐Term Fluctuations in Coastal Ocean Acidification and Hypoxia

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