Estimating Trends of Population Decline in Long-Lived Marine Species in the Mediterranean Sea Based on Fishers' Perceptions
2011

Trends in Marine Species Populations in the Mediterranean Sea

Sample size: 106 publication 10 minutes Evidence: moderate

Author Information

Author(s): Maynou Francesc, Sbrana Mario, Sartor Paolo, Maravelias Christos, Kavadas Stefanos, Damalas Dimitros, Cartes Joan E., Osio Giacomo

Primary Institution: Institut de Ciències del Mar, Consejo Superior de Investigaciones Científicas, Barcelona, Spain

Hypothesis

Can fishers' perceptions provide reliable data on the trends of marine species populations over time?

Conclusion

Fishers' perceptions indicate a significant decline in the populations of dolphins, turtles, and sharks in the Mediterranean Sea over the past 70 years.

Supporting Evidence

  • Fishers reported a significant decrease in dolphin sightings and incidental catches over the study period.
  • Shark catches were perceived to have diminished since the early 1940s for all species.
  • Fishers' perceptions align with scientific findings of declining marine populations.

Takeaway

This study shows that retired fishers believe there are fewer dolphins, turtles, and sharks in the Mediterranean Sea now than there were many years ago.

Methodology

Interviews were conducted with 106 retired fishers in Italy, Spain, and Greece about their perceptions of marine species populations over time.

Potential Biases

Fishers may have biases based on their personal experiences and the specific areas they fished.

Limitations

The study relies on the memories of fishers, which may be imperfect, and does not provide quantitative data for all species.

Participant Demographics

Participants were retired fishers aged 45 to 98, with extensive fishing experience ranging from 1922 to 1982.

Statistical Information

P-Value

p<0.05

Statistical Significance

p<0.05

Digital Object Identifier (DOI)

10.1371/journal.pone.0021818

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