Tasmania Rock Lobster Fishery (Australia)

Abstract

The commercial southern rock lobster (Jasus edwardsii) fishery is the second largest wild catch fishery in Tasmania, Australia, primarily exported to high-value Asian markets. The fishery occurs within one the fastest warming regions in the southern hemisphere. The climate-driven intrusion of the long-spined sea urchin (Centrostephanus rodgersii) has decimated key kelp forest lobster habitat as urchins overgraze the forests leaving ‘urchin barrens’. However, royalties from an abalone (Haliotis spp.) fishery in the same kelp habitat subsidise dedicated commercial fishing of C. rodgersii, which has helped control the urchin population. Community support and alternative markets also helped the lobster fishery respond to supply chain and trade policy disruptions associated with the COVID-19 pandemic, but cumulative ecological impacts of climate change, overfishing, and a lack of climate leadership continues to threaten resilience.

Climate Change and the Rock Lobster Fishery

Waters off the east coast of Tasmania are warming almost 4 times the global average (Hobday and Pecl 2014), however, Tasmanian southern rock lobsters not only face ocean warming but also enhanced interactions with potential competitors like the range-shifting eastern rock lobster, the world’s largest spiny lobster (Robinson et al 2015, Gervais et al 2021). Nonetheless, the resident southern rock lobster is not only more dominant in direct food competition than the range-shifting eastern rock lobster but also sustains competitive dominance beyond its physiological thermal optimum under predicted future ocean warming and heatwave scenarios (Twiname et al 2021). This, however, may come at a high energetic cost, which may impair the resident southern rock lobsters’ resilience to other stressors such as moulting, disease or other novel invasive species (Oellermann et al 2022).

While historical overfishing has lowered lobster population abundance, the stock status is considered sustainable due to intact age structure. Kelp forest loss due to urchin barrens and warming have eroded suitable habitat for lobsters. Although the high-value fishery provides wealth and reserves contributing to well-being, there is limited management capacity to address issues beyond day-to-day fishing responsibilities.

Lobster adult mobility is low and although larval dispersal is high, and there is no suitable poleward habitat available, past Tasmania. Access to economic opportunity via domestic markets facilitated adaptation to pandemic disruption. However, for climate stressors, high place attachment, low occupational mobility in the predominantly older workforce and the lack of climate-aware resilience mindsets largely prevent adaptation. Many management restrictions limit fishery flexibility (eg zoned fishing regions, stock rebuilding zones, catch limits, size limits, transiting closed areas), although the industry is engaging in some autonomous adaptations to the stressors of climate change (Pecl et al 2019). For example, in response to large mortalities of lobsters held in processor tanks, associated with warm water from the Tasman Sea 2015 heatwave (Oliver et al. 2017a, b), many operators have changed their landing practices so that they are unloading their (live) catch in areas with cooler waters (Pecl et al 2019).

Limited connectivity, since Tasmania is the last coastal habitat before Antarctica, prevents lobster redistribution. Strong social capital supported fishers’ transition to alternative markets, for example, during COVID. Participatory and transparent management arrangements could facilitate climate responses, if resources were made available. Moderate integration across scales and sectors facilitates collaboration and engagement between managers, industry and researchers.

A robust scientific system provides high access to knowledge and moderate learning capacity, which are key for evidence-based co-management. However, some denial of climate change within the industry and limited adaptive governance mechanisms may erode resilience. Prior to the extreme heatwaves of 2015/2016, acceptance of climate change was very low despite lobster fisher’s observations of changes in the marine environment being almost entirely consistent with climate change (Nursey-Bray et al. 2012).

In the co-management structure, fishers have strong agency and leadership but there is also a disconnect between quota owners and fishery operators in terms of industry goals and agency. The fishery is in need of a leadership champion to push forward climate adaptation.