In a new report, NOAA Fisheries describes how electronic technologies, including web and app-based data collection programs, may improve the agency's estimates of marine recreational catch. The report finds "opt-in," or non-mandatory, angler reporting apps to be appropriate for collecting qualitative data that support citizen science-based studies. But for these apps to produce population-level estimates of recreational catch, a large proportion of anglers would have to consistently use them to report accurate information about their fishing trips, and a statistically valid probability-based sampling survey would have to validate self-reported data, monitor the extent of reporting, and account for unreported trips.
The report (PDF, 12 pages) is part of the MRIP Action Plan on Implementing Electronic Reporting. Its recommendations are based on an external review of electronic reporting options for recreational fishing surveys, as well as our own assessment of two projects that evaluate the use of iAngler and iSnapper to collect recreational fisheries data.
Electronic reporting is a method of data collection that can include smartphones, tablets, and other technologies used to record, send, and store data. When electronic reporting is part of a probability-based sampling survey design, it has the potential to reduce data collection costs and improve the quality of reported information. But when recreational catch estimates are produced with only those data collected through an opt-in website or mobile app, the estimates are likely to be biased.
Challenges to Opt-in Angler Reporting Apps
Reporting Rates
Even with extensive outreach and education campaigns, voluntary apps such as iAngler and iSnapper suffer from low recruitment and retention rates. In addition to introducing the potential for bias, low reporting rates can negatively impact estimate precision.
Selection Bias
Estimates derived from data voluntarily reported through an angler app are susceptible to extreme selection bias, to the extent that anglers using the app fish differently from anglers not using the app.
Sampling Methods
Opt-in angler reporting apps are a non-probability sampling technique: the probability that an angler will use these apps is unknown. Sampling theory for non-probability surveys is poorly developed, and non-probability sampling and estimation methods follow no single standardized approach. As this report states, non-probability surveys cannot reliably produce scientifically sound population statistics without a consistent standard to support a valid sampling design.
Appropriate Uses for Electronic Reporting
Statistically valid survey designs that employ electronic reporting have been used to produce population-level estimates of recreational catch. In 2018, for example, NOAA Fisheries certified Alabama’s Snapper Check and Mississippi’s Tails n’ Scales “capture-recapture” survey designs. Both surveys use a mobile app as the primary mode of collecting recreational red snapper fishing data during the “capture” phase. A mandatory, probability-based dockside intercept survey qualifies angler reporting during the “recapture” phase.
NOAA Fisheries remains committed to identifying ways electronic reporting can improve our recreational fishing surveys. Later this year, NOAA Fisheries will begin working with the South Atlantic Fishery Management Council to explore: What motivates anglers to use mobile apps;What anglers are willing to report through mobile apps; and what impacts the recruitment and retention of app users.