The chlorophyll-a gradient as primary Earth observation index of marine ecosystem feeding capacity

Druon, JN, Mangin, A, Helaouët, P and Palialexis, A 2021 The chlorophyll-a gradient as primary Earth observation index of marine ecosystem feeding capacity. Journal of Operational Oceanography, 14 (5), supplement 1. 82-90.

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An efficient ocean management for fisheries requires accurate data over large spatial scales. The horizontal gradient of chlorophyll-a (and the derived mesozooplankton habitat index) exemplifies a plankton-to-fish index in support of a sustainable ocean management that targets fisheries and ecosystem productivity. The gradient of chlorophyll-a, as expressing the productivity of fronts, showed to be active long enough to sustain the development of mesozooplankton and to attract predators. In the global ocean, the chlorophyll-a gradient characterizes about 10 to 20% of the phytoplankton productivity that is transferred along marine food chains. Despite the warming of the surface ocean over the period 2003-2019, the global area-averaged trend of frequency of chlorophyll-a gradients, which is associated to the mesozooplankton feeding habitat and fish productivity, appears to be slightly positive with, however, contrasted regional trends.Daily values of chlorophyll-a gradient can be computed at global scale for the last two decades as well as up to near real-time. This is critical to improve our understanding of the plankton-to-fish dynamics, especially under the current effects of climate change, and to build observation-based operational products that will inform the future spatial and dynamic ocean management. The computation of such gradient requires a specific expertise in ocean colour, making them difficult to obtain for non-specialists. Their operational availability could therefore offer a critical benefit to ecosystem modelers and marine biologists and, in turn, to regional fisheries management facing overexploitation and the effects of climate change. Marine policies such as the EU Common Fisheries Policy and the Marine Strategy Framework Directive will ultimately be efficiently supported by the use of chlorophyll-a gradient as a direct, observation-based, biological variable monitoring the marine ecosystem productivity across a wide range of spatial and temporal scales.

Item Type: Publication - Article
Additional Keywords: Chlorophyll, Marine Ecosystem, Feeding
Subjects: Data and Information
Earth Observation - Remote Sensing
Ecology and Environment
Marine Sciences
Divisions: Marine Biological Association of the UK > Other (MBA)
Depositing User: Tamar Atkinson
Date made live: 25 Mar 2022 12:14
Last Modified: 09 Feb 2024 16:57

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