Dolphin diets indicate significant changes in the ocean may shorten food chains

Jan 10, 2018 03:23 PM EST | By Staff Reporter

Close
Dolphin Diets Suggest Extreme Changes in the Ocean May Shorten Food Chains
Dolphin Diets Suggest Extreme Changes in the Ocean May Shorten Food Chains

Dolphin Diets Suggest Extreme Changes in the Ocean May Shorten Food Chains: Extreme marine conditions like El Niño are associated with shorter food chain length in the California Current ecosystem, a new analysis reports. The finding counters previous evidence for long-term stability and ecosystem resilience in nitrogen cycling and food web structure off the coast of southern California.

While the impacts of environmental changes on specific marine organisms have been well examined, less is understood about impacts on food web dynamics -- due to a lack of methods that measure food web length over time. To further investigate such changes in food web structure, Rocio Ruiz-Cooley and colleagues studied the short-beaked common dolphin, Delphinus delphis, as an ecosystem indicator because dolphins are known to integrate chemical characteristics of their habitat through their diets. Ruiz-Cooley et al. traced nitrogen isotopes to track how amino acids in food sources at the base of the food chain eventually reached the dolphins. These proxies of food chain length exhibited strong declines after the 1997 to 1999 El Niño Southern Oscillation event, and after 2004, coinciding with a reduction in dissolved oxygen in the water.

The authors propose that three main factors could contribute to the isotope changes: shifts in diet between optimal and suboptimal prey, significant changes in community assemblages of the deep scattering layer (where a range of marine animals are found) and shifts in nitrogen cycling that affect plankton. Trends of declining dissolved oxygen concentration and stronger El Niño events have become more evident in recent years and are predicted to continue. As such, the authors say their approach could be used for future monitoring efforts to understand variability in food chain length in response to climate change.

© 2018 Food World News. All rights reserved. Do not reproduce without permission.

SHARE YOUR THOUGHTS

Get the Most Popular Food Stories in a Weekly Newsletter
Food Biz
Savory And Sweet Bites Perfect For Independence Day

Savory And Sweet Bites Perfect For Independence Day

While there's a wealth of cocktails to celebrate Independence Day, it's not easy to come by dishes that get into the spirit. The ones out there though are super fun!

Hotel San Francisco's New Subterranean Glam Rock Bar, Downunder

Hotel San Francisco's New Subterranean Glam Rock Bar, Downunder

Hotel San Francisco, a trendy bar in the Financial District named in reference to the Eagles song Hotel California, has officially opened its new downstairs extension, Downunder.

Food Tech
Here's How Nestlé's Sweet Earth Stays True To Its Roots, With Plant-Based Awesome Burger On The Horizon

Here's How Nestlé's Sweet Earth Stays True To Its Roots, With Plant-Based Awesome Burger On The Horizon

The plant-based meat industry is fast moving into the next phase of growth, and a hot topic at the Plant Based World Conference and Expo in New York

Mobile Apps

5 Best Apps To Help Track Your Macronutrients

However this is not all that the body needs. It’s not only about keeping out too many calories, but ensuring at the same time you are putting in all the right nutrients.

Real Time Analytics