Toni Cannard

Globally, marine protected areas (MPAs) have been designated with the aim of protecting marine biodiversity, primarily from extractive activities such as fishing. Most MPAs also include a range of zones with different fishing or other activities allowed in each, generally referred to as partially protected areas (PPAs). How these zones are implemented is often subject to disagreement between the impacted interest groups. Opposition to zoning may, in some cases, be the result of political lobbying or other interventions to stall or influence the process. In this study, we identify the key objectives considered by Australian MPA managers when planning uses in different areas of MPAs as well as their relative importance to decision-making. We also assess their relative importance from the perspective of fisheries managers, who are also responsible for the management of the primary users of the PPAs. We apply the modified analytic hierarchy process using data collected in a national survey of both groups. We find that both place the highest importance on achieving ecological objectives, but the importance of different economic and social objectives varies significantly between the groups. This may result in conflict not over the designation of conservation critical areas but over which activities are allowed in the PPAs.

Marine protected areas (MPAs) have been implemented globally to protect marine habitats and enhance biodiversity, often displacing commercial and recreational fishing activities previously occurring in the area. While the ecological impacts of MPAs have been the subject of considerable attention, the economic impacts on the displaced sectors have generally received less consideration. In this study, we examine the impacts of increasing the proportion of fully protected area within a coastal MPA—the Moreton Bay Marine Park in Queensland, Australia—on the economic performance of the fisheries operating in the area. This MPA is relatively unique as it is located adjacent to a major metropolitan area and, hence, heavily used for a range of activities. Analysis of commercial catch data suggests that the commercial fishery has been less impacted than expected by the loss of available area, although this result varies by species. Comparing fishing activity in the Bay with that in adjacent regions (assumed to reflect the counterfactual), we find evidence of strong improvements in fishery performance of the prawn trawl fleet, no significant change in fish net and line fisheries, and a small but significant decline in the performance of crab fishers. The impact on recreational fishing is uncertain as other external factors obfuscate the impacts of the rezoning.

Demands on freshwater for human use are increasing globally, but water resource development (WRD) has substantial downstream impacts on fisheries and ecosystems. Our study evaluates trade-offs between WRDs and downstream ecosystem functioning considering alternative dam and water extraction options, diverse eco-hydrological responses and catchment-to-coast connectivity. We used a data-driven ensemble modelling approach to quantify the impacts of alternative WRDs. WRD impacts varied from weakly positive to severely negative depending on species, scenario and cross-catchment synergies. Impacts on fishery catches and the broader ecosystem (including mangroves) increased with catchment developments and volume of water removed, or if flow reduced below a threshold level. We found complex, linked-catchment dependence of banana prawns on flow and floods. Economic risks for this important fishery more than doubled under some scenarios. Sawfish emerged as the most sensitive across a range of WRD scenarios. Our findings highlight the need to consider marine ecosystems and fisheries to inform sustainable management of the world’s remaining free-flowing rivers.

Over the past 50 years, the diversity of fisheries types being actively managed has changed from mainly data-rich, industrial sectors to more socially, economically, and environmentally complex multispecies and multisector fisheries. Accompanying this change has been a broadening of management objectives to include social and economic considerations with traditional resource sustainability objectives, the so-called triple bottom line, and the need to include these considerations into harvest strategies. The case of a line fishery in Australia’s Great Barrier Reef is used as a demonstration of the first steps in implementing triple bottom line harvest strategies. This fishery has several disparate sectors including commercial, tourism, and recreation; targets multiple but important reef species; and is undertaken in a World Heritage Site. This work highlights the need for a much-expanded set of objectives elicited from stakeholders that are either included in the trade-off analyses of the different harvest strategies or directly in an optimization. Both options demonstrated that a paradigm shift is required to emphasize representative participatory management systems that assemble teams from quite different backgrounds and viewpoints; use much broader set of objectives; and modify tools and (especially) the data collected within revised monitoring programmes to underpin these tools.

Policies aiming to preserve vegetated coastal ecosystems (VCE; tidal marshes, mangroves and seagrasses) to mitigate greenhouse gas emissions require national assessments of blue carbon resources. Here, we present organic carbon (C) storage in VCE across Australian climate regions and estimate potential annual CO₂ emission benefits of VCE conservation and restoration. Australia contributes 5–11% of the C stored in VCE globally (70–185 Tg C in aboveground biomass, and 1,055–1,540 Tg C in the upper 1 m of soils). Potential CO₂ emissions from current VCE losses are estimated at 2.1–3.1 Tg CO₂-e yr^-1, increasing annual CO₂ emissions from land use change in Australia by 12–21%. This assessment, the most comprehensive for any nation to-date, demonstrates the potential of conservation and restoration of VCE to underpin national policy development for reducing greenhouse gas emissions.