Diet Changes in Striped Dolphins Due to Overfishing
Author Information
Author(s): Gómez-Campos Encarna, Borrell Assumpció, Cardona Luis, Forcada Jaume, Aguilar Alex
Primary Institution: University of Barcelona
Hypothesis
Does overfishing of small pelagic fishes affect the diet of striped dolphins in the Mediterranean Sea?
Conclusion
The study found that over the last two decades, the diet of striped dolphins has shifted from primarily consuming sardines and hake to a more diverse diet due to changes in food availability.
Supporting Evidence
- In 1990, hake and sardine contributed to 60% of the diet of immature striped dolphins.
- By 2007-2008, the diet of both immature and mature dolphins became more diverse, with hake and sardine contributing to less than 40%.
- δ15N values decreased from 1990 to 2007-2008, indicating a dietary shift.
Takeaway
Striped dolphins used to eat a lot of sardines, but now they eat a mix of different fish because there are fewer sardines available.
Methodology
The study analyzed stable isotope signatures in the muscle of stranded striped dolphins and compared dietary changes over two decades using a Bayesian mixing model.
Potential Biases
Potential biases in diet assessment due to reliance on stranded samples and the limitations of stable isotope analysis.
Limitations
The study relied on stranded dolphins, which may not represent the entire population, and the sample size from the later period was relatively small.
Participant Demographics
116 stranded striped dolphins (61 females and 55 males) from the western Mediterranean.
Statistical Information
P-Value
0.0037
Confidence Interval
95% credibility interval
Statistical Significance
p<0.05
Digital Object Identifier (DOI)
Want to read the original?
Access the complete publication on the publisher's website