This post comes to us from Sharon Nieukirk, Senior Research Assistant:
As a marine mammal acoustician (studying the sounds produced by marine mammals) I am typically in an office, and my recorded data come to me. Other members of our team deploy the recorders or “hydrophones” Haru described in a previous blog, and they sway on their moorings in remote oceans of the world, recording the sounds of the sea. However, last week I had a chance to go into the field to collect acoustic data in person as part of an (e)DNA project led by OSU researchers Dr. Scott Baker and Dr. Holger Klinck. The main objective of this project is to “develop next-generation sequencing methodology for detection and species identification of cetaceans using environmental (that’s the “e”) DNA collected from seawater”. What this means in layman’s terms is Dr. Baker is developing a method to detect what species of animals have moved through a portion of a bay or ocean by collecting water samples and looking at the DNA present in that sample.
Sounds a lot like something out of the TV show CSI, doesn’t it? The method is still under development, and to test this idea the team conducted a series of experiments in the vicinity of killer whales near San Juan Island in Puget Sound. We started with killer whales because the population is well known, the whales are relatively accessible from shore and Puget Sound is a semi-enclosed ocean environment. During August and September, the team spent two weeks at the University of Washington’s Friday Harbor Laboratory (FHL), and launched our small 18’ boat each day to find the whales and sample water. Friday Harbor is an amazing place to work on killer whales; there are numerous researchers working in the area (i.e. NOAA, Center for Whale Research), there is a thriving whale watching industry which also collects killer whale information (Orca Network) and virtually the entire island is “wired for sound” with listening stations set up to monitor the vocalizations of killer whales (Salish Sea Hydrophone Network). After touching base with others working in the area, we’d leave the FHL dock in the early morning, proceed to an area where killer whales had been spotted….and get in line. The number of boats, from both U.S. and Canadian ports, in the vicinity of whales is truly staggering. Luckily, there are strict rules for how you should behave when you are near killer whales… and just in case you forget the rules the volunteers from Soundwatch will pay you a visit.
An advantage of this research technique is that we didn’t need to be close to the whales, we just needed to move into an area where the whales had been. We would wait for the whales to come past us, throw our current drogue in the water to mark the water mass where the whales had been, and then began sampling. Sampling involved taking water samples, towing a net through the water to maximize the chance of concentrating trace DNA and recording sound in the vicinity of the animals.
Recordings are important as they help us to identify the particular killers whales that passed through the water mass because individual groups of killer whales produce very specific vocalizations (see Listening to Orcas). At the end of the day, we’d head back to FHL, filter the water samples and freeze the filtrate for further analysis. Dr. Baker and Debbie Steel are working hard on analyzing all of the water samples collected during this fieldwork. Stay tuned to see if killer whales have left their mark on the waters of Puget Sound……
Click here to hear an example of sounds we recorded from killer whales while in the field last week (may require headphones).