New Zealand Sea Lions Historic and Present Day Threats

Past Distribution Present Distribution

Life history Estimated maximum age: females 28yrs, males 23yrs Age at first reproduction: females 4 yrs, males 9+ yrs Reproductive rate: females 64% Adult survival not well defined – juvenile survival highly variable Population estimate 2008/09: 9880 (95% CI, )

Breeding Sexually dimorphic: females 160 kgs, males 400 kg Dominant males hold territories, females move between territories Polygynous breeders: December - January Females nurse 8+ months Females are highly philopatric Colonial during breeding but disperse widely outside breeding season

68 % of all NZ sea lion dives at Auckland Islands exceed estimated ADL (4-10% for other otariids) Mean aerobic dive limit Feeding ParameterAuckland IslandsOtago Age at first breeding4yrs < 5% of all females4yrs >85% of all females Female mass (8-13yrs)112 kg152 kg Foraging trip distanceup to 175 km (ave 102km)up to 25 km Foraging trip duration66 hours<24 hours Dive Depthave 130m, max 600mave 50m, max 110

Interaction with people Sea lions are sometimes curious and playful and are usually unafraid

IUCN red list 2009: Vulnerable due to low population in decline DoC Threat classification 2005: Range restricted – conservation dependent Current Population Status

Bacterial outbreaks Fisheries bycatch Fisheries competition Present Threats

Fisheries – Direct By-catch Estimated by-catch SQUID 6T SeasonFRML (revised) Estimated total number NZ sea lion mortalities % observer coverage Number NZ sea lion captures on observed boats % females caught Total Tows * *62 (124) (150) (95) Total780153Ave. 70%17205 * Court ruling allowed fishing to continue after FRML reached + Minister of Fisheries increased FRML at request of fishery

Diet of the New Zealand sea lion occurrence (%O), number (%N) and mass (%M) TOTAL (121 stomachs)DIGESTED (112 stomachs) 1 to 2 + days before death FISH%O%N%M%O%N%M Jack Mackerels Warehou Pigfish Barracouta Javelin fish Hoki Red cod Ling Opalfish CEPHALOPODS Octopus Arrow squid Total number of taxa/species 3529

Protection measures Marine mammal protection act: - it is an offence, amongst other things, to harass or disturb marine mammals; - offences carry penalties of up to 6 months imprisonment or fines up to $250,000 and further fines of up to $10,000 for every marine mammal in respect of which the offence is committed; - marine mammals caught accidentally or incidentally in fisheries must be reported Marine mammal sanctuary: since 1994 there has been a 12 n.mile marine mammal sanctuary around the Auckland Islands

Protection measures Fisheries Act: - the Minister may take measures considered necessary to avoid, remedy, or mitigate the effect of fishing-related mortality on any protected species (ie Fisheries Related Mortality Limit, FRML) FRML: - in place since FRML supposed to allow population growth - bycatch estimated using historical catch data when observer coverage was low and has not been adjusted to account for 50% longer tows - model used to calculate FRML severely limited (unable to fit estimated reproductive rate) - FRML does not include other fisheries (just SQ 6T) - legal challenges have allowed continuation of fishing after FRML has been passed.

Protection measures Sea Lion Exclusion Device (SLED): - impact on sea lions/rate of survival unknown - 35% discount factor attributed to boats using approved SLED based on poor data DoC Population Management Plan: - would allow DoC to set mortality limit but currently abandoned