Page History

Report: http://www.ices.dk/reports/FTC/2005/SGUFM05.pdf

Fishing mortality (F) is defined by The Study Group on Unaccounted Mortality in Fisheries (ICES, 1995) as "'The sum of all fishing induced mortalities occurring directly as a result of catch or indirectly as a result of contact with or avoidance of the fishing gear'"

...

The most important of these are:
Fb, Fd, Fe, and Fg

Note: UFM == unaccounted fishing mortality

Illegal, Unreported, and Unregulated fishing (IUU):

...

• IUU can start a "self propagating cycle" (they cite Schmidt 2004)
  • IUU by one fisherman induces other fishermen to go IUU
  • More IUU --> more uncertainty in estimates --> stricter regulations --> more IUU
  • Paton, 2005 says that IUU can become part of the culture of a fishing village

Estimating IUU

• "In a review for the FAO-IPOA, Evans (2000) explains that considerable progress could be made in accounting for IUU fishing by simply improving monitoring and data collection programs"
  • suggest using "satellite imagery vessel detection systems" to get more data
• Statistical Methods
  • Compare catch data to trade data
  • Estimate IUU: estimate number of unregulated boats, extrapolate catch rates
    • "reliant on the collection of a complex array effort and catch data"
    • assumes that legal fishing is representative of IUU
• Model Methods
  • population models: use survey data and CPUE, find difference between predicted mortality rate and actual mortality rate
    • result could just be that the model was not totally accurate for a given year
  • "quasi-quantitative Monte-Carlo integration": all data on UFM is combined into one analysis. "Each regieme is scored with respect to its influence on under-reporting; the values being based on available data"
    • They cite Ainsworth and Pitcher, 2005; Pitcher et al, 2002; Pitcher and Watson, 2000
    • What does ^^ even mean?
  • models of IUU behavior; surveillance encounter probabilities: consider that a surveillance ship finding a fishing ship (either leagl or not) is a "random sample." Use this to extrapolate and estimate total IUU levels. (also needs to consider that IUU boats will avoid detection more than legal boats)
    Note: population model method will give a confidence interval

Discards

• 1994 FAO estimates are 19.9 to 39.5 megatonnes of global catch were discarded (that about 30% of the total catch)
• estimate downgraded to 20 megatonnes in 1998; then 7.3 megatonnes in 2005 (8% global catch) (recent estimates not comparable--different methods)
• EU Data Collection Regulation (Commission Regulation) #1639/2001 has something to do with reporting discards
• "Still difficult to determine the accuracy...in most discard estimations"
• Calculating: direct (stand on the boat and count) or indirect:
  • estimation of small fish discards made by comparing length measurements from observers on the boat can be compared to length estimates on land
  • I'm not sure how that would work...they cite Palsson et al, 2002; Palsson 2003; sokolov 2003
  • results from studies about fishing gear selectivity
    • I assume that this means that you look at a net and say "wow, this will give a 10% catch that is < 10 inches" and then look at catch data and say "wow, there are only 8% of that size, the rest must have been thrown back."
  • analyze catch length frequencies, assume that all fish shorter than the limit are thrown back
  • interview fishermen
  • get data from fishermen

Escape Mortality

• "Selective fishing gears...can be justified only if significant numbers of escaping fish survive"
• studies indicate that mortality is species-specific
  • cod, haddock survive well
  • herring does not survive well
• Team 2 should read PDF page 16

Ghost Fishing

• New nets are not biodegradable--when they get loose they are permanent death machines
• In deep water (>200m), ghost fishing can last for years (several year old nets are still active in Canada)
  • In shallow water the nets get fouled
    • I don't know what fouling really means

The group working on quotas should read starting on PDF page 18.