Common Jack Mackerel Catch, Effort and CPUE

Catch, Effort and CPUE

Catches of Jack Mackerel in Tasmanian waters that are reported in the General Fishing Returns have been variable, mostly fluctuating between 2.6 and 59.8 t until 2007/08, when there was a sharp increase in purse seine effort targeting Jack Mackerel on the east coast that lasted three years (Figure below). Over the assessed time series, Jack Mackerel catches peaked at 919.6 t in 2008/09, then declined sharply in 2010/11 and 2011/12 to around 60 t because the major purse seine operator ceased activities. In 2020/21, only 396 kg of Jack Mackerel were landed in Tasmania, following similarly low catches in the preceding eight years (Figure below). Targeted purse and beach seine catches were historically taken mostly from the southeast coast but incidental catch in recent years was taken as by-product by beach seine mostly from the northwest coast (Figure below).

Notably, between 1995 and 1999, purse seine catches of Jack Mackerel were taken as part of a separately documented fishery (Zone A fishery) ranging from 447 t in 1995/96 to 8,458 t in 1997/98 and averaging 4,485 t per year for that period. These data are not presented in Figure above.

Jack Mackerel is not an important recreational species in Tasmania. Estimates of recreational catch range from approximately 1-5 t, or 1-200 t less than the commercial catch for the year in which estimates were made (Figure above).

The use of purse seine gear by one major operator between 2008/09 and 2009/10 resulted in a peak in effort and catch during this short period (Figure above). Beach seine effort has been declining slowly over time, noting that Jack Mackerel represents a by-product of the beach seine fishery and no meaningful CPUE trends can be drawn from these data (Figure above). With the exception of the years in which the purse seine fishery actively targeted Jack Mackerel, purse seine CPUE has remained low as the species has not been targeted in Tasmanian waters (Figure above).

The full 2020/21 Scalefish Assessment, released Dec 2022, can be found at the link:

Latest Scalefish Assessment