Cetaceans and sea turtles in the northern region of the Mediterranean Cetacean Migration Corridor: abundance and multi-model habitat suitability analysis

IF 2.8 2区生物学 Q1 MARINE & FRESHWATER BIOLOGY

Frontiers in Marine Science Pub Date : 2025-05-02 DOI:10.3389/fmars.2025.1496039

Luis Cardona, Natalia Amigó, Jazel Ouled-Cheikh, Manel Gazo, Carla A. Chicote

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Abstract

The Mediterranean Cetacean Migration Corridor is one of the largest marine protected areas in the Mediterranean Sea. Nevertheless, little is known about the abundance and distribution of cetaceans and sea turtles in the area. A combination of aerial and boat surveys conducted in 2023 revealed the presence of seven cetaceans and two sea turtle species therein. The community was dominated numerically by two epipelagic foraging species, the striped dolphin (Stenella coeruleoalba) and the loggerhead turtle (Caretta caretta). However, based on population estimates, the majority of the community biomass was contributed by sperm whales (Physeter macrocephalus) and fin whales (Balaenoptera physalus). The population numbers of Cuvier’s beaked whales (Ziphius cavirostris) and Risso’s dolphins (Grampus griseus) were in between. When migrating fin whales were excluded from the analysis, deep divers with a high trophic position (sperm whales, Cuvier’s beaked whales and Risso’s dolphins) made a much larger contribution to the overall community biomass than epipelagic predators with a lower trophic position (striped dolphins and loggerhead turtles). Bottlenose dolphins (Tursiops truncatus), long-fined pilot whales (Globicephala melas) and leatherback turtles (Dermochelys coriacea) were observed during the surveys, but were too scarce to attempt any population estimate. Random forest models and generalized additive models identified the concentration of chlorophyll-a and the eastward current velocity as the major drivers of the distribution of epipelagic species. Conversely, the distribution of deep divers was best explained by a combination of bathymetric (standard deviation of the slope) and hydrographic (eddy kinetic energy, sea surface height and eastward or northward sea water velocity) variables. Finally, the distribution of fin whales was poorly predicted by the environmental variables considered. This evidence indicates that dynamic spatial closures might be needed to reduce the impact of fishing and maritime traffic on epipelagic predators, whereas static closures might suffice for deep divers.

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地中海鲸类迁徙走廊北部地区鲸类和海龟：丰度和多模式生境适宜性分析

地中海鲸类迁徙走廊是地中海最大的海洋保护区之一。然而，人们对该地区鲸类动物和海龟的数量和分布知之甚少。2023年进行的空中和船只调查显示，其中有7种鲸目动物和2种海龟。群落数量上以条纹海豚（Stenella coeruleoalba）和红海龟（Caretta Caretta）两种上层觅食物种为主。然而，根据种群估计，大部分群落生物量是由抹香鲸（Physeter macrocephalus）和长须鲸（Balaenoptera physalus）贡献的。居维叶喙鲸（Ziphius cavirostris）和里索海豚（grpus griseus）的种群数量介于两者之间。当迁徙的长须鲸被排除在分析之外时，具有高营养地位的深海潜水员（抹香鲸，居维叶喙鲸和里索海豚）对整个群落生物量的贡献要比营养地位较低的上层捕食者（条纹海豚和红海龟）大得多。在调查期间观察到宽吻海豚（Tursiops truncatus），长鳍领航鲸（Globicephala melas）和棱皮龟（Dermochelys coriacea），但由于数量太少，无法进行任何数量估计。随机森林模型和广义加性模型均表明，叶绿素-a浓度和东流流速是上层海洋物种分布的主要驱动因素。相反，深海潜水者的分布最好由水深（坡度的标准差）和水文（涡流动能、海面高度和向东或向北的海水速度）变量的组合来解释。最后，考虑到环境变量，长须鲸的分布预测很差。这一证据表明，可能需要动态空间封闭来减少捕鱼和海上交通对上层海洋捕食者的影响，而静态封闭可能足以满足深海潜水员的需求。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Frontiers in Marine Science Agricultural and Biological Sciences-Aquatic Science

CiteScore

5.10

自引率

16.20%

发文量

2443

审稿时长

14 weeks

期刊介绍： Frontiers in Marine Science publishes rigorously peer-reviewed research that advances our understanding of all aspects of the environment, biology, ecosystem functioning and human interactions with the oceans. Field Chief Editor Carlos M. Duarte at King Abdullah University of Science and Technology Thuwal is supported by an outstanding Editorial Board of international researchers. This multidisciplinary open-access journal is at the forefront of disseminating and communicating scientific knowledge and impactful discoveries to researchers, academics, policy makers and the public worldwide. With the human population predicted to reach 9 billion people by 2050, it is clear that traditional land resources will not suffice to meet the demand for food or energy, required to support high-quality livelihoods. As a result, the oceans are emerging as a source of untapped assets, with new innovative industries, such as aquaculture, marine biotechnology, marine energy and deep-sea mining growing rapidly under a new era characterized by rapid growth of a blue, ocean-based economy. The sustainability of the blue economy is closely dependent on our knowledge about how to mitigate the impacts of the multiple pressures on the ocean ecosystem associated with the increased scale and diversification of industry operations in the ocean and global human pressures on the environment. Therefore, Frontiers in Marine Science particularly welcomes the communication of research outcomes addressing ocean-based solutions for the emerging challenges, including improved forecasting and observational capacities, understanding biodiversity and ecosystem problems, locally and globally, effective management strategies to maintain ocean health, and an improved capacity to sustainably derive resources from the oceans.