A dynamic subtropical coastal hotspot of benthic foraminifera in the Southeastern Mediterranean indicates early-stage tropicalization

被引：2

作者：

Manda S. ^{[1
]}

Herut B. ^{[2
]}

Rilov G. ^{[2
]}

Kucera M. ^{[3
]}

Morard R. ^{[3
]}

Abramovich S. ^{[1
]}

Ashckenazi-Polivoda S. ^{[4
,5
]}

机构：

[1] Department of Earth and Environmental Sciences, Ben Gurion University of the Negev, POB. 653, Be'er Sheva

[2] National Institute of Oceanography, Israel Oceanographic and Limnological Research, POB 9735, Haifa

[3] MARUM Centre for Marine Environmental Sciences, University of Bremen, POB 330440

[4] Dead Sea and Arava Science Centre, Masada National Park, Mount Masada, Dead-Sea

[5] Ben-Gurion University of the Negev, Eilat Campus, Eilat

来源：

Science of the Total Environment | 2024年 / 945卷

基金：

以色列科学基金会;

关键词：

Benthic ecology; Climate change; Foraminifera; Invasive species; Macroalgae; Southeastern Mediterranean; Tropicalization;

D O I：

10.1016/j.scitotenv.2024.173917

中图分类号：

学科分类号：

摘要：

Due to ongoing ocean warming, subtropical environments are becoming accessible to tropical species. Among these environments are the vermetid reefs of the Southeastern Mediterranean (SEM). In the last decades, these valuable coastal habitats witnessed the proliferation of numerous alien species of tropical origin. Among the meiofauna thriving on these reefs are benthic foraminifera, single cell marine organisms that make a significant contribution to global carbonate production. It has been widely recognized that benthic foraminifera among are invasive species thrive in the macroalgal cover, and it has been suggested that their populations are becoming a significant new source of sediment substrate. Here, we report on the first systematic assessment of the population size of the benthic foraminifera, allowing a comparison with data from the native tropical habitat of these species. Our study is based on a seasonal sampling of benthic foraminifera from confined sampling areas at four sites along the vermetid reef platforms of the Israeli SEM coast. Our survey reveals a patchy distribution of each species with peak population densities exceeding 100,000 specimens per m2, making the SEM a hotspot of benthic foraminifera, with population densities comparable to tropical coral reef environments. The assemblages of the SEM hotspot are dominated by cosmopolitan foraminiferal taxa and tropical invaders from the Indo-Pacific (e.g., Amphistegina lobifera, Pararotalia calcariformata, soritids, and Hauerina diversa). In contrast to foraminiferal hotspots in the tropics, which are completely dominated by larger symbiont-bearing taxa, the SEM hotspot stands out due to high abundances of non-symbiont-bearing species Textularia agglutinans and small miliolids. An intriguing observation is the significant heterogeneity in composition and density of foraminiferal assemblages between the vermetid reefs' southern and northern areas (Israel), indicating that the productivity of the dominant species are also modulated by local yet unknown environmental factors. © 2024 Elsevier B.V.

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