We’ve almost made it! The year 2020 is just about to end and 2021 is right around the corner. Though many issues that were highlighted in 2020 won’t be going away in 2021 and need to continue to be addressed, there are some things to look forward to. Just this month, healthcare workers started receiving the first round of the COVID-19 vaccine. As more and more people get vaccinated, we will hopefully see the end of strict quarantine measures in the near future. Maybe we will even be able to spend the 2021 holidays with family without a mask in sight! 2021 will also bring a new administration with climate change as a top priority, which will likely influence ocean policies and management. So, while 2020 was an important year and we should not forget what we learned in it, here’s to hoping that 2021 doesn’t throw us any detrimental curveballs.
Now that you’re up to date on some of what’s happening in the USA, let me update you on what I’ve been working on. In my last blog post I outlined how I’m using the Oregon Department of Fish and Wildlife’s (ODFW) daily angling license sale data to determine if marine reserves have influenced recreational fishing. Since people are no longer able to fish in the marine reserve sites, we might expect this to result in fewer licenses purchased in towns near the reserves post implementation. This might also be observed by an increase in licenses purchased in towns further from the reserves.
However, whether or not people decide to go fishing is just one aspect of measuring a potential reserve effect on recreational fishing communities. For those that do decide to go fishing, how much they catch and over what time period is another crucial component. This metric is referred to as Catch Per Unit Effort (CPUE). For our analysis, we calculate CPUE by dividing the total number of fish caught by the number of anglers aboard the vessel and by the number of hours fished. This creates a standardized metric whereby we can compare fishing trips with varying numbers of anglers and hours fished. Specifically, we can compare CPUE reported at docks near marine reserves pre- and post-marine reserve implementation. We might expect that marine reserve site closures could increase effort, thereby decreasing CPUE, by forcing anglers to spend more time traveling further to avoid the reserves. On the other hand, we might expect site closures to increase catch, thereby increasing CPUE, due to spillover effects whereby a greater abundance of fish inside the reserves leads to a greater abundance of fish outside the reserves.
Lucky for me, ODFW has been collecting the information I need to calculate CPUE through the Ocean Recreational Boat Survey (ORBS). This is an annual survey of Oregon’s marine recreational fishery that estimates both catch and effort at the top 10-11 ocean access points. This survey was first developed in 1979, but the original focus was on generating accurate salmon estimates in a timely manner. The ORBS survey has since expanded and provides valuable data on stock abundance and health for many species, which is used for management purposes.
By looking at both daily angling license sales as well as CPUE on charter boats, we should be able to uncover any potential marine reserve effects on the recreational fishing community. Of course, there are many covariates to take into account that could influence CPUE, such as catch regulations and environmental variables. I won’t dive into this right now, but maybe another blog post detailing the difficulties of finding downloadable historical buoy data without huge gaps is in order. Signing off for now, happy New Year!
I never thought about using CPUE as a social science metric, but it makes perfect sense. Always interesting to see data being used for various purposes. What are ODFW’s estimates of certainty around CPUE? Do they think there’s a certain about of unlicensed catch happening in the reserves?