Here is a Red-Abalone-Info graphic about abalone management that might help understand the HCRs Harvest Control Rules used in the abalone FMP by the TNC.
I have also included a write up IMPROVEING ABALONE MANAGEMENT
(Using Simple Transparent Scientific Principles)
By Jack Likins and Jack Shaw
Three years ago The Nature Conservancy (TNC) organized a small group of scientists and fishermen to try and work with the CDFW to improve management of the Northern California recreational abalone fishery. Cooperation from the CDFW with both fishermen and outside scientist has been lacking. Because of this, the group developed an independent set of Harvest Control Rules (HCR). We are asking that our Harvest Control Rules be considered equally with whatever HCRs the CDFW develops using an independent outside scientific peer review. We strongly feel that our HCRs are an improved method of understanding and managing the abalone fishery.
Harvest Control Rules (HCR)
All Fisheries Management Plans (FMP), including our north coast red abalone management plan, use a set of “Harvest Control Rules” (HCR) and indicators/data that help scientists and the public understand the health and status of the fishery.
Our simple HCRs use two main sets of data (indicators). They are size (length) and catch (number of abalones caught by fishermen). Neither of these indicators is currently used by the DFW to manage our fishery.
Size or length data can be used to determine how much successful reproduction is occurring among abalones in the ocean. The scientific term used for this is “Spawning Potential Ratio” or SPR. Using SPR to assess a fishery is science-based and internationally accepted, not only for abalones, but for most spawning marine species. The easiest way to understand SPR is that it is a ratio between the “spawning potential” of an area which is fished divided by the “spawning potential” of that same area if it were unfished (no fishing). Data is collected by divers in the water measuring the length of abalones without removing them. In-water size measurements of abalones are used to calculate SPR.
Size data is collected by easily trained “citizen scientists” who look for and measure the sizes of all the abalone they can readily see (no need to follow a transect line). From experience on the north coast, up to 200 size measurement can be made on a single dive.
Because size data can be collected inexpensively by “citizen scientists”, more data can be collected from more places and more often than the very expensive density data collected by the CDFW. This will give managers the ability to assess more areas than the current 10 index sites and do it more regularly than once in 3 years as is currently the case for density data collection.
CATCH (fisherman’s actual landings)
Catch or landings data comes directly from the report cards that we submit to the CDFW every year. Scientist can use the actual numbers of abalones caught at each of the 56 report card sites to determine “Catchmsy”. Catchmsy is the “Maximum Sustainable Yield” or MSY of a particular site. In other words, it is the maximum catch or “fishing pressure” that the site can produce and still be sustainable.
Putting Size and Catch Together into a Decision Tree
When these two data steams (size and catch) are weighted and put into a Decision Tree they become a powerful tool to assess the health of the abalone in our fishery. The data and Decision Tree are used to make clear, transparent scientific decisions about how to increase or decrease “Total Allowable Catch” (TAC) in the fishery. TAC is then transparently and objectively increased or decreased by using things like daily limits, annual limits, size limits, etc. to insure the long-term stability and sustainability of the fishery.
Management Stategy Evaluation (MSE)
The most interesting thing the MSE found was that density data, the way it is collected and used by the CDFW, is unreliable and leads to incorrect decision-making (TAC adjustments).
A “Management Strategy Evaluation” or MSE is used to scientifically and statistically help determine which set of indicators/data are most reliable in accomplishing our management goals of long term stability and sustainability. A MSE is a computer simulation used to predict what will happen to the abalone fishery 5, 10 and 25 years into the future. MSEs are used to evaluate Fisheries Management Plans (FMP) and the Harvest Control Rules (HCR), which are included in FMPs. The uses of MSEs are well documented and accepted internationally as good fisheries management practice. The MSE that was used to evaluate our HCRs and the DFW’s HCRs was specifically designed to evaluate our red abalone fishery here on the north coast and take into account the scientifically proven natural life cycle of our abalones. An MSE accounts for both fishing and natural deaths, including deaths due to extreme environmental events. An MSE predicts what will happen at various levels of fishing pressure. This information can then be used to annually adjust TAC for sustainability.