24 Monitoring Threatened Species and Ecological Communities
some cases this baseline can help to inform the desired state of the mammal fauna
towards which monitoring can chart progress.
Monitoring of Australian marine mammals
The principal focus of this chapter is on monitoring of the terrestrial mammal
fauna, primarily because this is where recent losses have been so pronounced
(Woinarski et al. 2014). However, some features of monitoring of the marine
mammal fauna are noted brief ly.
There are high profile global monitoring programs for most of the harvested
(or formerly harvested) large cetacean species, and results from these monitoring
programs have been instrumental in partly regulating the whaling industry. In a
few cases, regional and global monitoring has demonstrated some recovery
following cessation of whaling, with a notable example being the extraordinary
increase in Australian subpopulations of the humpback whale Megaptera
novaeangliae (Noad et al. 2016). However, monitoring is inadequate or non-existent
for other whale species in Australian waters.
Monitoring of population trends for seals and sea-lions is possible because the
entire breeding population is episodically concentrated at breeding colonies.
However, even this monitoring can be difficult because some species have many
small and remote breeding sites, and interpretation of results is challenging for at
least some species (notably the Australian sea-lion Neophoca cinerea) because
intervals between breeding periods are more than 1 year, and breeding activity is
not tightly synchronised among different colonies. Nonetheless, this monitoring
has been instrumental in the listing and uplisting of some species, and
documenting ongoing trends for decline for some species (e.g. Australian sea-lion)
notwithstanding some remedial management actions (Goldsworthy and Page 2007;
Shaughnessy et al. 2 011).
There are also long-established monitoring programs, mostly based on aerial
survey, for the dugong Dugong dugon (in parts of its range), with the results of such
monitoring inf luential in conservation planning and the management of
traditional hunting (Marsh et al. 2004; see also Chapter 22). Aerial survey is also
increasingly used for monitoring for some coastal dolphin species.
In contrast, there is little or no monitoring for most other cetacean species in
Australian waters. As a consequence, there is little information on the population
size and trends for most Australian marine mammals, to such an extent that the
conservation status of most species cannot be reliably assessed: 35 of 59 Australian
marine mammal taxa were considered to be Data Deficient (Woinarski et al. 2014).
In addition to some direct monitoring of some threatened marine mammal
species, by-catch (including of threatened marine mammals) is also monitored in a
range of fishing industries, but it is challenging to relate such tallies to population-
level impacts (Campbell et al. 2008; Lack et al. 2014).