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SSC Report to CFMC
Meeting held 24-25 June 2011
Caribbean Fishery Management Council Meeting
28-29 June 2011
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SSC addressed the following:CFMC interest in (expressed by RA Crabtree) setting OFL
levels above average landings for healthy stocksUsed the ORCS Working Group Approach (Berkson et al.
2011) to determine OFL and make recommendations to CFMC regarding ABC Determined if an FMU was lightly, moderately or heavily
exploited – associated with a scalar to apply to the landing statistic
Determined the time series of landings on which to base OFLDetermined the landings statistic(s) to be used as the basis for
determining OFLApplied the scalar to the landing statisticABC calculation
SSC classified FMUs as to whether they were at low, moderate, or high risk of being overfished
Council is responsible for the scalar to apply to OFL to get ABC
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CFMC asked SSC to consider the following: CFMC asked the SSC to consider setting OFL
levels above average landings for healthy stocksRA Crabtree provided rationale: “If the you
believe a stock is healthy with no signs of overfishing, but you then set the OFL at average catch, aren't you then saying that overfishing has been occurring on average about half the time? Isn't that inconsistent with the starting premise that the stock is healthy? So if a stock healthy, shouldn't the OFL be a level above average catch?”
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SSC ResponseSetting OFL equal to average catch over a period of
time does not mean that overfishing occurred about half the time.
Catch can fluctuate and can be higher if fishing is maintained at Fmsy (fishing morality rate at MSY (Maximum Sustainable Yield).
However, managing by a constant fishing morality strategy requires info on stock size and fishing mortality so that catch can be adjusted annually.
When average catch is used to estimate fishing mortality this information is lacking – constant catch strategy required.
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CFMC request continued
RA Crabtree also pointed out that the Gulf of Mexico Council’s SSC has been working on the following:“Based on expert evaluation of the best
scientific information available, recent historical landings are without trend, landings are small relative to stock biomass, or the stock is unlikely to undergo overfishing if future landings are equal to or moderately higher than the mean of recent landings...... Set the overfishing limit equal to the mean of recent landings plus two standard deviations. “
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SSC ResponseThe conditions for applying this approach (i.e., landings
without trend, landings small relative to stock size, stock unlikely to undergo overfishing) are not generally applicable to Caribbean stocks because of insufficient information.
Furthermore, the CFMC SSC is not aware of a scientific basis for assuming that OFL occurs at a "catch equal the average plus two standard deviations.”
This corresponds to assuming that a catch that occurred rarely (about 2.5% of the time) during the averaging period could have been taken as a constant catch without overfishing. Why should this be true in general?
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OFL Determination using the ORCS (Only
Reliable Catch Stocks) Working Group Approach
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Step One Determine if an FMU (Fisheries Management Unit)
was lightly, moderately or heavily exploited using evidence-based scoring system of selected attributes.Commercial and recreational landings were scored
separatelyCommercial: Six of the nine original attributes were scored
for each FMU based on criteria provided in the ORCS reportRecreational: 3 – 4 of the attributes were scored for each
FMUAttributes were scored as follows:
1 – low level of exploitation2 – medium level of exploitation 3 – high level of exploitation
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Attributes Table – Example Results for Puerto RicoAttributes Porgies Goatfish Jacks Angelfish
Exploitation1 Not Included
Refugia2 3 3 3 3
Behavior3 2 2 2 2
Morphology4 2 1 2 2
Bycatch5 2 3 2 1M = Natural mortality6 2 2 2 2
Rarity1 Not Included
Value7 1 2 1 1
Trend1 Not Included
Average 2.00 2.17 2.00 1.83Ecological value 2
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Explanation of attributes REFUGIA - Presence of
extensive natural or managed refugia. This applies to species that were not highly mobile as adults in relation to the size of the refugia. Value of 1 - less than 50% of habitat is accessible to fishing, 2 - 50-75%, 3 - >75%.
SCHOOLING, aggregation, or other behavior responses affecting capture by fishing gear. Species specific behavior characteristics can make a species more or less susceptible to capture by a fishing gear.
School of yellowtail snapper – schools of yellowtail are harvested with seine nets on St. Thomas/St. John.
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Explanation of attributes (cont.)Morphological
characteristics affecting capture, i.e. large spines, body shape.
Targeting of stock - Is the stock targeted by the fishery or is it bycatch. Stocks that are primarily bycatch are likely to be lightly exploited relative to the targeted stocks. However non-targeted stocks may still become overfished if it is less productive than the targeted stock.
Four-eye butterfly fish susceptible tocapture by traps and nets because of itsbody shape. It is bycatch.
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Explanation of attributes (cont.)
Natural mortality - For stocks subject to similar fishing mortality rates, those with low natural mortality have a higher likelihood of becoming overfished than those with a higher natural mortality.
Blue fry – high natural mortality
Graysby – moderate to high natural mortality
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Explanation of attributes (cont.)Highly valued fish stocks
are more susceptible to overfishing or becoming overfished.
Surgeonfish are considered trash fish in Puerto Rico – sell for $0.75/lb.
Red grouper (below) and mutton snapper (above) are highly valued stocks in the U.S. Caribbean.
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Recommended scalar to apply to OFLsStock Category
Lightly exploited B > B 65%
Moderately exploited
B approximately BMSY
Heavily exploitedB < B 20%
2.0 X catch statistic
1.0 x catch statistic
0.5 x catch statistic
Corresponding Average Attribute Values
< 1.5 1.5 – 2.5 > 2.5
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ResultsAverage attribute
scores ranged from 1.67 for tilefish to 2.5 for spiny lobster
Therefore, all FMUs, including both commercial and recreational landings, were determined to be moderately exploited and the scalar applied was 1.0 x the catch statistic
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Step two – Selection of Time Series for Puerto RicoLandings time series from
1988 – 2009 was selected.Expansion factors for
landings prior to 1988 were unknown
Prior to 1988 landings may have included catches from outside the Puerto Rican EEZ
After 1988, the DNER lab has institutional knowledge of the expansion factors and the rationale supporting their application to annual landings
Landings data for Puerto Rico
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Step two – Selection of Time Series for Puerto Rico (cont.)
Landings from 1988 onwards show a high degree of variability potentially owing to a variety of factors Natural variability in fish
populations Accuracy of data
% of fishers reporting Accuracy of self-reported
landings in the past because of difficulty in accurately identifying species and more recently because fishers are asked to report and submit trip tickets without port samplers assistance
Misreporting because of discontent with new regulations
Landings data for Puerto Rico
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Step two – Selection of Time Series for Puerto Rico (cont.)Expansion calculations
changed in 2003 from participation based calculation to fish weight based calculation.
Declines in reported data likely because of many fishers not submitting trip reports because of discontent with new regulatory regime.
In conclusion, no substantial time period is free of changes and impacts.
Landings data for Puerto Rico
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Commercial Landings – Step 3: Selecting an appropriate landings statistic The SSC selected the median* of the commercial landings
values for the time series 1988 – 2009 for each FMU with adequate landings data as the basis of OFL.
Rationale: More robust to errors of measurement Less sensitive to outliers
Three FMUs (Angelfish, Surgeonfish and Tilefish FMUs) were treated differently.
They are not commercially targeted in Puerto Rico because they are considered either trash fish (surgeonfish, tilefish) or 2nd class fish (angelfish) and sold for $0.75 - $1.00/lb
These three FMUs had very low reported commercial landings that didn’t reflect what was considered sustainable for the fishery.
These were considered pre-emptive quotas – quotas for underdeveloped fisheries that the CFMC would probably not want to get out of hand.
The SSC selected two times the highest annual recreational landings recorded as the basis for commercial OFL for the Angelfish, Surgeonfish and Tilefish FMUs.
* Median = middle value in a range of values, with half the values above the median and half below the median
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Recreational Landings – Step 3: Selecting an appropriate landings statistic Landings were based on
MRFS data which was available from 2000 – 2009
OFL based on Median for FMUs with
annual landings in most if not all years
For FMUs with a median value of 0 (Angelfish, Tilefish, Surgeonfish) the maximum landings were the basis for OFL
MRFSS does not gather data on spiny lobster. The SSC based the OFL for spiny lobster was the 2005 SFA Amendment that allocated 32% of total spiny lobster landings to the recreational sector
Table 1: OFL values based on selected statistic measures x 1.012 x max rec landings, 2median, 3 maximum, 4rec landings = 32% of total landings
FMU GroupCommercial
Landings(lbs)Recreational Landings(lbs)
Total Landings(lbs)
Angelfishes 11,9781 5,9893 17,967Aquarium Trade 4,9532 5,9202 10,873
Boxfish 95,6832 5,1292 100,812
Goatfishes 19,5172 4022 19,919
Grunts 202,6622 5,5872 208,249Jacks 95,6212 56,6682 152,289
Lobster 364,3552 171,4614 535,816
Others 39,8612
Porgy 27,4882 2,8632 30,351
Squirrelfish 18,5142 4,3232 22,837
Surgeonfishes 9,5721 4,7863 14,348
Tilefish 10,8461 5,4233 16,269
Trigger and filefish 64,9722 24,3652 89,337
Wrasses 60,1632 5,6112 65,774
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Calculation of ABC from OFL -Two step processStep 1 –
responsibility of SSC:SSC classifies each FMU
as to whether it is at low, moderate or high risk of becoming overfished due to its productivity.High productivity – low
risk (short life span, fast growth, etc.) Example: sprat, fry, herring.
Low productivity – high risk (large grouper species).
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Porgies Goatfish JacksAngel-fish Grunts
Surgeon-fish
Squirrel-fish Boxfish Wrasses
Trigger-fish
Tile-fish
Spiny Lobster
M L M M M L L M H M M H
Table 4: Risk levels as determined by the SSC for FMUs not overfished or undergoing overfishing. L = low risk of becoming overfished, M = moderate risk, H = high risk.
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Calculation of ABC from OFL -Two step process (continued)Step 2 –
responsibility of CFMC:
The CFMC decides on the scalar needed to multiply by the OFL to get ABC.
The scalar is based on the SSCs determination of risk (previous table)
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Risk Level Alternative A*
Alternative B
Alternative C
Alternative D
Low risk (high productivity)
0.75 x OFL 0.75 x OFL 0.90 x OFL 0.90 x OFL
Moderate risk (moderate productivity)
0.75 x OFL 0.75 x OFL 0.75 x OFL 0.80 x OFL
High risk (low productivity)
0.75 x OFL 0.50 x OFL 0.50 X OFL 0.70 X OFL
Table 5 (Table 6 (Berkson et al. 2011). Example ABC options for catch-only stocks using the ORCS Working Group Approach. *Note the example scalars provided in each column remain equal or decrease as you read down the columns as risk increases (productivity decreases).
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US Virgin IslandsGiven that the SSC only met for two days, the SSC
did not re-address their recommendations for OFL and ABC for St. Thomas/St. John or St. Croix. OFL and ABC recommendations remain as previously presented.
Note: The time series for St. Thomas/St. John and St. Croix is short because fishers in the USVI only started recording landings by fish family at the turn of the century.
There is no recreational data in the USVI, so the OFL is based only on average commercial landings.
OFL’s for St. Thomas/St. John and St. Croix Districts The time series for determining average annual
catch for commercial landings of species listed in Tables 2 and 3 of the Options Paper dated December 22, 2010 (spiny lobster and reef fish) shall be the longest time series available for both islands; for STT/STJ 2000- through the most recent year for which reliable data are available and for STX 1999-through the most recent year for which reliable data are available.
OFL Recommendations
The SSC recommends [Action 1(b)] Option 2(b) under Table 7* and that OFL equals the average annual commercial landings for the year sequences selected in the previous motion. *Refers to Option Paper dated 22 Dec 2010 School of stoplight parrotfish
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ABC Recommendation
For STT/STJ, STX, and Puerto Rico, the SSC recommends ABC=OFL (for species listed in Tables 2, 3, 4, and 5 of the Options Paper dated December 22, 2010) except for the Acanthuridae (reef herbivores) and most Pomacanthidae (reef spongivores). Because these species may play a significant ecological role in regulating algal and sponge populations of the coral reefs, the SSC recommends that a new option under Action 1(b), Option 2(i) ABC = OFL x (0.50) for the Acanthuridae and the Pomacanthidae be considered.
Acanthuridae - surgeonfish
Pomacanthidae - angelfish
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SSC Rationale for New Option
SSC is proposing this the new option because of the severe decline in coral and the increase in the abundance of algae and the high abundance and competitive dominance of sponges:
Acanthurids are herbivores and as such may be important in helping regulate algal populations on the reef.Angelfish: At least the larger species of angelfish (rock beauty, French, and queen) feed on sponges and as such may have a keystone species role in protecting corals from erosion by boring sponges and overgrowth by sponges.
Juvenile French angelfish
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Impact of sponges on coral reefs•French angelfish, queen angelfish, and rock beauty were found to feed mainly on sponges (volume of sponges in stomachs was 74.8%, 96.8%, and 97.1% by volume, respectively).•Sponges are currently abundant in Caribbean coral reef communities.•Sponge biomass, diversity, and abundance can exceed that of corals.•Sponges can overgrow, kill and or dissolve the skeletons of corals.•Predation on sponges from hawksbill turtles and angelfishes has been compared to herbivory on plants. •Even though other factors such as disease or storms may play an important role in regulating sponge populations, it is important to view FMUs in an ecosystem context.
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Aquarium SpeciesThe SSC recommends the following preferred alternative for the Aquarium Species (Options Paper dated December 22 2010): Action 2, Option 2, Sub-option C: Move all of the aquarium trade species listed in both the Fishery Management Plan for Corals and Reef Associated Plants and Invertebrates of Puerto Rico and the U.S. Virgin Islands, and in the Reef Fish Fishery Management Plan of Puerto Rico and the U.S. Virgin Islands, into a separate Fishery Management Plan specific to aquarium trade species.
Spirobranchus giganteus, Christmas tree worm
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SSC Recommendations•Puerto Rico – expanded landings from 2003 to present should be calculated using the participatory expansion method so that data from 1988-2002 can be compared with 2003 – 2009. If the reults differ significantly, a correction factor should be developed. Once this is done, the SSC may need to revisit their decision.•Puerto Rico – SSC recommended that the data and expansion factors for the 2005 landings be reviewed. The peak appears to be anomalous.•The SSC noted that their was no connection between level of fishing and MSY. Only if a stock assessment is done should MSY be included in the discussion of fishing levels.
Hawksbill Turtle - STX
