Habitat patches that cross marine reserve boundaries: consequences for the lobster Jasus edwardsii

Abstract

The spatial configuration of marine reserves should reflect management objectives. If reserves are intended to conserve 'natural' biological communities, then reserve boundaries should follow barriers to species movement, but if cross-boundary movement of harvestable individuals associated with certain habitat is desired for fisheries purposes, then boundaries should intersect that habitat. We relate movement patterns of the reef-associated spiny lobster Jasus edwardsii (Palinuridae) to the relative positions of habitat and reserve boundaries in a 24.5 km 2 marine reserve on the temperate northeast coast of New Zealand by tagging > 5000 individuals and recapturing a subset over 3 yr using pots. Lobster movement patterns were sex-and size-dependent, but nearly all recaptured individuals were found on the same rocky reef on which they were tagged, indicating that lobsters were reluctant to cross the muddy sediments between reefs. Lobsters became increasingly likely to migrate from the reserve into the heavily fished adjacent coast as the proportion of their reef that was unprotected increased. Corresponding changes in average catch per unit effort (CPUE) and size of all lobsters (tagged and untagged) occurred within the protected parts of the reefs, with lobster densities on a fully protected reef being 8-fold higher than densities on the protected part of a reef that was 91% unprotected. KEY WORDS: Exploited species · Habitat boundary · Tag-recapture · Marine protected areas Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 388: [159][160][161][162][163][164][165][166][167] 2009 relates to the proportion of habitat patches exposed to fishing has not been documented for any species.The spiny lobster Jasus edwardsii (Hutton, 1875) (Palinuridae) is common on temperate rocky reefs around New Zealand and southern Australia. It is heavily fished in most regions and typically increases in size and abundance when protected within no-take marine reserves (Edgar & Barrett 1999, Kelly et al. 2000. In northeastern New Zealand, its recovery in marine reserves appears to have contributed to shifts in rocky reef community structure , Shears & Babcock 2002. J. edwardsii undertake seasonal inshore-offshore movements that can exceed 5 km and are associated with moulting and reproduction (MacDiarmid 1991, Booth 1997, Kelly 2001, Gardner et al. 2003, Kelly & MacDiarmid 2003. Smaller lobsters tend to move further than larger lobsters , Kelly & MacDiarmid 2003.We determined how the spatial relationship between habitat patches and reserve boundaries affects the spiny lobster Jasus edwardsii within and adjacent to the fully-protected Te Tapuwae o Rongokako Marine Reserve in temperate northeastern New Zealand. This 24.5 km 2 reserve was established in November 1999 and average densities of legal-sized (≥54 mm tail width for males, ≥60 mm tail width for females) lobsters within it have since increased from 20 ind. ha -1 in 2000 to 180 ind. ha -1 in 2005, while densities outside ha...

Net contribution of spillover from a marine reserve to fishery catches

“…Prolongation of the current study and a recent 20% expansion of the CIMR into adjacent lobster grounds may, in a few years, provide further illustration of the tradeoffs between biomass recovery, MPA size, and permeability. In a recent study of Jasus edwardsii, Freeman et al (2009) showed that lobsters became increasingly likely to migrate from an MPA into adjacent fished areas as the proportion of protected reef and thus lobster density in each reef correlated positively with the proportion of the reef that was protected. Expansion of the CIMR would increase the proportion of contiguous lobster habitat closed to fishing and predictably lead to reduced spillover.…”

Activity patterns of wild European lobster Homarus gammarus in coastal marine reserves: implications for future reserve design

“…Previous studies have successfully assessed the effectiveness of closed areas for large decapods with tag-return methodology, e.g. blue crab Callinectes sapidus (Lambert et al 2006) and spiny lobster Jasus edwardsii (Freeman et al 2009). These studies have underlined the importance of habitat as an essential underlying mechanism driving movement patterns in the species studied.…”

MPA policy: What lies behind the science?

“…The argument for 'spillover' that there is a net movement of fish across MR boundaries to exceed the lost catches of fishermen [57] is widely cited both in the scientific literature [58,59], and certain policy discourses (see Section 4.3), but it is highly dependent on the type of habitat (e.g. coral/rocky reefs), layout of habitat [60], mobility [61,62] and life-history [63,64] of the species in question. Additionally, rigorous scientific testing for spillover has rarely been achieved.…”