What question did this study set out to answer?

This research aims to quantify long-term ecological changes in Greek coastal lagoons over four decades.

January 22, 2026Open Access

Four Decades of Changes in Greek Coastal Lagoons (Amvrakikos Gulf, Northwest Greece): A Multi-Indicator Ecological Analysis

TZTheodore ZouliasHellenic Centre for Marine Research MVMaria VlachouUniversity of Thessaly SRSofia ReizopoulouHellenic Centre for Marine Research

Key Points

This research aims to quantify long-term ecological changes in Greek coastal lagoons over four decades.
Analyzed four decades of fisheries data from six lagoons in the Amvrakikos Gulf
Used ecological indicators for assessing trophic structure and ecosystem responses
Conducted cluster analysis to identify shifts in species contributions to total yield
Calculated trends in total yield, primary production, and temperature of the catch
Identified a distinct regime shift in fishery production in the late 1990s to early 2000s
Mean total yield consistently declined across lagoons, with values between 2.7 to 7.2 t km−2
Primary production required showed a decline, while mean catch temperatures increased in most lagoons
Pelagic to demersal ratios generally decreased, indicating changing ecological dynamics
Predictions for future yields remain within historical levels, with varying carrying capacities among lagoons

Abstract

Coastal lagoons are highly vulnerable to human and climatic pressures, yet long-term ecological changes remain poorly quantified. We analyzed four decades (1980–2020) of data from fisheries from six lagoons in the Amvrakikos Gulf, Greece, using ecological indicators to assess trophic structure, exploitation status, and ecosystem responses. Cluster analysis of species level fishery production revealed a distinct temporal regime shift in the late 1990s–early 2000s, reflecting a major reorganization of species contributions to total yield. Mean total yield (Y), showed a consistent declining trend across lagoons, ranging from 2.7 ± 2.0 to 7.2 ± 5.0 t km−2. Primary Production Required (PPR) declined (0.8–1.5 × 1010g C km−2 yr−1), while Mean Temperature of the Catch (MTC) increased in five lagoons (19.0–21.4 °C) and remained stable in one (20.0 ± 0.9 °C). Pelagic to demersal (P/D) ratios generally decreased (0.09–1.26), and Q-90 values were variable (0.8–2.2), highlighting site specific ecological dynamics. Short term yield predictions for 2021–2025 ranged from 0.78 to 6.75 t km−2, remaining comparable to recent historical levels, while the estimated carrying capacities varied from 1.79 to 9.11 t km−2, reflecting contrasting exploitation states among lagoons. These results demonstrate that multi-indicator, fishery-based analyses provide a robust framework for quantifying ecological change and guiding adaptive management in lagoon ecosystems.

KI fragen

Bookmark

View Full Paper