Maintenance of old-growth size structure and fecundity of the red rock lobster Jasus edwardsii among marine protected areas in Fiordland, New Zealand

Cease or prohibit commercial fishing

A replicated, site comparison study in 2006–2007 of 12 rocky seabed sites in the Tasman Sea, Fiordland, New Zealand (Jack & Wing 2010) found that a zone excluding commercial fishing did not have a higher abundance of red rock lobster Jasus edwardsii compared to adjacent fished areas, after up to two years. Lobster abundance was similar in the exclusion zone (2 individuals/250 m²) and the fished areas (1 individual/250 m²). In 2006 and 2007, divers surveyed eight sites within a commercial fishing exclusion zone set in 2005, and four fished sites (at 15 m depth). Red rock lobsters were counted along 50 x 5 m transects (1 transect/site in 2006, 3/site in 2007).

(Summarised by: Anaëlle Lemasson)

Designate a Marine Protected Area and prohibit all types of fishing

A replicated, site comparison study in 2006–2007 of 26 rocky seabed sites in Fiordland, Tasman Sea, New Zealand (Jack & Wing 2010a) found that older marine protected areas prohibiting all fishing (no-take reserves) had more red rock lobsters Jasus edwardsii compared to younger ones, to a commercial fishing exclusion zone and to adjacent areas without designated protection. Lobster abundance was higher in no-take reserves >13-year-old established in 1993 (12 individuals/250 m²) compared to those <2-year-old established in 2005, commercial exclusion zones, and adjacent unprotected areas which had similar abundances to each other (1–2 individuals/250 m²). In 2006 and 2007, divers surveyed four no-take reserves established in 1993, ten no-take reserves established in 2005, eight sites within a commercial fishing exclusion zone set in 2005, and four unprotected fished sites. All sites were located at 15 m depth on rocky habitat. Red rock lobsters were counted along 50 × 5 m transects (1 transect/site in 2006, 3/site in 2007).

A replicated, site comparison study in 2008 of eight rocky seabed sites in Fiordland, Tasman Sea, New Zealand (Jack & Wing 2010b) found that marine protected areas prohibiting all fishing (no-take reserves) had different population structures of female red rock lobsters Jasus edwardsii, but not males, and greater egg production potential, compared to commercial fishing exclusion zones, but the effects varied with the age of the reserves. Population structure data were reported as size-frequency distributions. A 15-year-old reserve had greater abundance and size of female lobsters compared to commercial exclusion zones. One of two 3-year-old reserves had no lobsters (either male or female); in the other abundance and size of female lobsters were not significantly different to the other sites. Egg production was higher in the 15-year-old reserve (8,350/m²/year) compared to the commercial exclusion zones (1,260/m²/year). The 3-year-old reserve with lobsters had an egg production not significantly different to the other sites (3,400/m²/year). In 2008, divers surveyed two sites in each of the following: a no-take reserve established in 1993, two no-take reserves established in 2005, and a commercial fishing exclusion zone set in 2005. All sites were located at 15 m depth on rocky habitat. Red rock lobsters were counted along three 50 × 5 m transects, and their size and sex assessed from video footage (see study for details). Egg production potential was estimated using abundance and size data for female lobsters.

(Summarised by: Anaëlle Lemasson)