Achieving conservation and restoration outcomes through ecologically beneficial aquaculture

Abstract

A range of conservation and restoration tools are needed to safeguard the structure and function of aquatic ecosystems. Aquaculture, the culturing of aquatic organisms, often contributes to the numerous stressors that aquatic ecosystems face, yet some aquaculture activities can also deliver ecological benefits. We reviewed the literature on aquaculture activities that may contribute to conservation and restoration outcomes, either by enhancing the persistence or recovery of one or more target species or by moving aquatic ecosystems toward a target state. We identified 12 ecologically beneficial outcomes achievable via aquaculture: species recovery, habitat restoration, habitat rehabilitation, habitat protection, bioremediation, assisted evolution, climate change mitigation, wild harvest replacement, coastal defense, removal of overabundant species, biological control, and ex situ conservation. This list may be expanded as new applications are discovered. Positive intentions do not guarantee positive ecological outcomes, so it is critical that potentially ecologically beneficial aquaculture activities be evaluated via clear and measurable indicators of success to reduce potential abuse by greenwashing. Unanimity on outcomes, indicators, and related terminology will bring the field of aquaculture–environment interactions into line with consensus standards in conservation and restoration ecology. Broad consensus will also aid the development of future certification schemes for ecologically beneficial aquaculture.

Oyster reef restoration - aquaculture interactions: maximizing positive synergies

“…The growing fields of conservation aquaculture (Froehlich et al, 2017;Wasson et al, 2020;Ridlon et al, 2021) and restorative aquaculture (Theuerkauf et al, 2019b;Carranza and Zu Ermgassen, 2020;Overton et al, 2023) recognise the important role aquaculture can play in supporting conservation efforts. Oyster aquaculture can benefit oyster reef restoration by: (1) providing contemporary knowledge and historical context of those conditions and sites that maximise oyster recruitment, growth and survival; (2) providing resources, such as water quality and environmental data, stock and genetic resources for projects that require seeding, and shell substrate; and (3) providing environmental and biological conditions, and stewardship, that support healthy reefs (Ridlon et al, 2021;Ridlon et al, 2023).…”

“…In other parts of the world, such as eastern Australia and the USA, hatcheries and their selective breeding programs are being harnessed to supply seed for restoration (termed, "conservation aquaculture", Froehlich et al, 2017;Wasson et al, 2020). These hatchery-produced spat are often selectively bred for desirable traits such as rapid growth and disease resistance and in some instances also resilience to warming waters (Naciri-Graven et al, 1998;O'Connor and Dove, 2009;Tan et al, 2020;Nascimento-Schulze et al, 2021;Overton et al, 2023). Larvae may be settled onto sanitised shell (cultch) in the hatchery or pediveliger larvae can be transported to the reef restoration location and settled onto cultch using remote settlement techniques (Fitzsimons et al, 2020).…”

Evaluation of Larval Sea Lamprey Petromyzon marinus Growth in the Laboratory: Influence of Temperature and Diet

“…In the past two decades, advances in technology and standards of practice have expanded the role of aquaculture. Specifically, aquatic organisms can now be cultured to offset wild captures of declining populations, restore degraded habitats by shifting to terrestrial-based culture, and aid in species recovery [2][3][4]. The development of "conservation aquaculture"-defined as "the use of human cultivation of an aquatic organism for the planned management and protection of a natural resource"-holds significant promise to support the sustainable use of natural resources and species requiring management intervention [5].…”

Global principles for restorative aquaculture to foster aquaculture practices that benefit the environment

“…When done well, with the right practices and in the right locations, aquaculture can create a range of benefits to the environment, from the provision of habitat and improved water quality, to assisting migration, coastal defense, and biological control (Overton et al, 2023). As such, there is an opportunity to decrease the occurrence or risk of negative impacts from aquaculture and enhance positive impacts, by identifying, acknowledging, and ultimately increasing the use of practices that can provide restorative outcomes.…”