Ever wonder how scientists study fish populations? Or what kind of data is needed to determine how many fish we can safely catch each year?
This May I traveled behind the scenes of fisheries management as a volunteer on the National Marine Fisheries Service
rockfish survey. I boarded in San Francisco Bay on May 15th
, one of the windiest days this spring. I was a little apprehensive boarding the ship in rough weather, especially since the day before one of the crew members lost the tip of his finger due to complications with the winch in high winds! We set out to sea just as the sun was setting and head to Pt. Reyes to begin our first trawl for krill, squid, and juvenile fish. This was the beginning of 8 crazy
Each spring and summer, the NMFS scientists from the National Oceanic and Atmospheric Administration (NOAA
) conduct surveys along the west coast to collect data on our fisheries. These data help improve our understanding of fish biology, generate stock assessments
and ultimately determine catch limits (how many fish we can safely catch year year).
So how does this relate to my research? Well, for the last four years I have studied the ecology of an important commercial and recreational fishery (rockfishes) in Dr. Todd Anderson’s Fish Ecology Lab
. My research
seeks to understand the factors that affect population replenishment of rockfishes, such as food availability, oceanography and larval movement. I was so excited to participate in this year’s survey of rockfish populations off our coast because we were catching record numbers of migrating larval and juvenile rockfish. When we caught particularly large numbers of fish, I found myself brainstorming questions and hypotheses: Why did we catch so many fish near Monterey Canyon? Was it a coincidence that we caught large numbers of krill and
rockfish in the same trawl? By participating in surveys off-shore of my field sites, I was able to gain new insight into my study species and how they have been studied by NMFS for decades.
In each trawl we bring up some fascinating looking creatures! The crew used a crane to lift the net over the collection bins and we all gathered around in anticipation. It’s always a surprise! Here are some of my favorite animals that we caught.
This is Phronima
, a crustacean that eats the inside of a gelatinous creature called a salp and then lives inside its body. Does this bizarre creature look familiar? Maybe you’ve seen it featured as an alien in a movie?