Decadal changes in the structure of Cymodocea nodosa seagrass meadows: Natural vs. human influences

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• 作者：Fern ; o Tuya ; Lu铆s Ribeiro-Leite ; Noelia Arto-Cuesta ; Josep Coca ; Ricardo Haroun ; Fern ; o Espino
• 关键词：seagrass ; water quality ; decline ; human-mediated impact ; Canary Islands
• 刊名：Estuarine, Coastal and Shelf Science
• 出版年：20 January, 2014
• 年：2014
• 卷：137
• 期：Complete
• 页码：41-49
• 全文大小：1772 K

文摘

Seagrass meadows are deteriorating worldwide. However, numerous declines are still unreported, which avoid accurate evaluations of seagrass global trends. This is particularly relevant for the western African coast and nearby oceanic archipelagos in the eastern Atlantic. The seagrass Cymodocea nodosa is an 鈥榚cological engineer鈥?on shallow soft bottoms of the Canary Islands. A comparative decadal study was conducted in 21 C.聽nodosa seagrass meadows at Gran Canaria Island to compare the structure (shoot density, leaf length and cover) between 2003 and 2012. Overall, 11 meadows exhibited a severe regression, while 10 remained relatively stable. During this period, natural influences (sea surface temperature, Chlorophyll-a concentration and PAR light, as well as the number of storm episodes detaching seagrasses) had a low predictive power on temporal patterns in seagrass structure. In contrast, proximity from a range of human-mediated influences (e.g.聽the number of outfalls and ports) seem to be related to the loss of seagrass; the rate of seagrass erosion between 2003 and 2012 was significantly predicted by the number of human-mediated impacts around each meadow. This result highlights promoting management actions to conserve meadows of C.聽nodosa at the study region through efficient management of local impacts.