Volunteer divers participating in the Reef Life Survey (RLS) program actively assist species conservation efforts by
generating data for threat assessments and population trend monitoring, through in-water restoration efforts,
and through outreach of marine conservation messages. Up to 2014, standardised underwater visual survey
data provided by RLS divers described densities of 495 cryptic fish species at over 1200 sites distributed around
Australia. Each species was recorded on 34 separate transect blocks on average, allowing the first assessments of
population trends for many species. These data highlight the threatened and data deficient status of endemic
Australian handfish species. At least five shallow-water handfish species are potentially threatened, including
the smooth handfish Sympterichthys unipennis, which has not been sighted for over 200 years, but is yet to be in-cluded on any threatened species list. RLS divers undertook directed searches at key historical locations for two
handfish species, the red handfish Thymichthys politus, now only known from a single reef, and Ziebell's handfish
Brachiopsilus ziebelli, with no confirmed sighting for over a decade. From a total of 100 h of underwater search
effort, only four red handfish were recorded, all at a site threatened by adjacent human activity. These and
other handfish species should be considered for inclusion on the IUCN Red List given that populations are either
very small or have vanished, spawning substrates have probably declined, and the species lack a larval dispersal
stage. More importantly, the absence of information on the conservation status of the majority of marine species
needs urgent attention, including through expanded citizen science efforts, if management intervention is to
occur and extinctions minimised.