The Green Sawfish is subject to intense fishing pressure that is poorly managed or unregulated across much of its range. The species is taken as bycatch in commercial and small-scale fisheries (inclusive of artisanal, cultural, and subsistence) with a variety of fishing gears including gillnet, trawl, and line. The toothed rostra of sawfish make them highly susceptible to entanglement particularly in gillnets and trawls. Fishing effort has increased over the past decades across most of the species’ range with the fin and meat trade driving increasing demand and exploitation of many elasmobranchs (Chen 1996, Jabado et al. 2017, Okes and Sant 2019, Yan et al. 2021). In most instances throughout the range of this species, it is retained for at least its fins, rostra, and meat (CITES 2007, Yan et al. 2021). Within Australia and other jurisdictions where fishers are required to release sawfishes, at-vessel- and post-capture-mortality of captured sawfishes may still be high as individuals may be euthanized or have their rostrum removed in order to safely or efficiently untangle them from fishing gear (Morgan et al. 2016).
The inshore freshwater, estuarine, mangrove, and coastal habitats used by the species are threatened by habitat loss and degradation (CITES 2007). For example, in Southeast Asia, mangrove areas have been reduced by an estimated 30% since 1980 (Polidoro et al. 2010). For Green Sawfish, habitat loss or degradation is most concentrated on essential nearshore and estuarine nursery habitats. There may also be impacts on adult Green Sawfish associated with offshore oil and gas extraction (e.g., seismic surveys) which occurs in several areas within their range (e.g., the Australian Northwest Shelf, northwest Indian Ocean).
Historically, the northwest region of Australia has been relatively undeveloped and sparsely populated, and as a result has large areas of undisturbed coastal habitats. At present, there are several additional factors that may pose major threats to Green Sawfish in Western Australia (WA). These include a range of coastal developments, including various mining and natural resource operations which have export facilities along the WA coastline (Devillers et al. 2015). These include oil and gas and mining operations that have export facilities along the coastline, as well as substantial salt mining operations with seawater intakes and outtakes and export facilities. These operations include coastal developments such as lighted jetties, dredged shipping channels, and offloading structures with sea walls. For juvenile Green Sawfish using this area, tracking data suggests that such structures may hinder small juveniles from moving along the coastline (K. Lear and D. Morgan unpubl. data 2022), and therefore the increased numbers of these structures appearing in WA could cause some population fragmentation or destruction of important juvenile habitats for this species.
