A review of reported seaweed diseases and pests in aquaculture in Asia

Abstract

Seaweeds have been used as a food for centuries in Asia and are increasingly exploited as a source for dietary supplements, animal feed, chemicals, and biofuels. In recent years, there has been an increase in the prevalence of diseases and pests in these aquaculture crops, with a subsequent reduction in their quantity and commercial value. In this article, we review diseases that have been reported in the scientific literature for species of red and brown seaweeds. We have focused on the major seaweed crops grown in Asia, where much of this production is centered. We also provide information on disease management and biosecurity and some observations on future directions.

An analysis of the current status and future of biosecurity frameworks for the Indonesian seaweed industry

“…The introduction of new species to combat the loss of vigour and the transportation of live seedlings or seed stock is often practiced to support the development of seaweed aquaculture (Bindu and Levine 2011;Valderrama et al 2015;Hayashi et al 2017;Hwang et al 2018;Hurtado et al 2019). However, these practices are well documented as major pathways for introducing and facilitating the spread of diseases and pests in seaweed aquaculture worldwide (Sulu et al 2004;Largo et al 2017;Loureiro et al 2017;Badis et al 2019;Ward et al 2019). For example, the documented infection of Porphyra/Pyropia in Europe and Asia with the pathogenic oomycete Olpidiopsis (Kim et al 2014;Badis et al 2019;Ward et al 2019) and outbreaks of the epiphytic pests Neosiphonia and Polysiphonia spp.…”

“…However, these practices are well documented as major pathways for introducing and facilitating the spread of diseases and pests in seaweed aquaculture worldwide (Sulu et al 2004;Largo et al 2017;Loureiro et al 2017;Badis et al 2019;Ward et al 2019). For example, the documented infection of Porphyra/Pyropia in Europe and Asia with the pathogenic oomycete Olpidiopsis (Kim et al 2014;Badis et al 2019;Ward et al 2019) and outbreaks of the epiphytic pests Neosiphonia and Polysiphonia spp. in Kappaphycus seedlings are both attributed to trading as a pathway for pest introductions (Hurtado et al 2019).…”

“…The biggest challenge for developing biosecurity capacity in the national strategy for the seaweed aquaculture sector is the generalization and grouping of the seaweed industry within the fisheries and aquatic animal industries frameworks. This makes implementation of biosecurity measures unclear, particularly regarding disease and pest management (Ward et al 2019). Current legislation, regarding quarantine protocols and the maintenance of healthy aquaculture systems, was typically directed towards fish and other aquatic animals, despite it being assumed that this legislation also included seaweed cultivation.…”

“…The fact, national quarantine process does not include for life seaweed neither for national trading nor for importation because lack of appropriate facilities and no clear regulation for seaweed quarantine process (R. Mustafa, Fisheries Officer at Dinas Kelautan dan Perikanan DKP, personal communication). The regular monitoring of seedling health status, traceability and the maintenance of a clean farm environment are also additional preventative measures that could help control diseases, such as 'iceice' (Marino et al 2019;Ward et al 2019). These measures are regularly applied in other aquaculture systems (Rodgers et al 2015;Jia et al 2017;Stentiford et al 2017).…”

“…Detection of diseases through standardized diagnostic techniques such as histopathology and DNA markers can help with earlier identification of the symptoms of a microbial pathogen and aid in the understanding of factors, which cause disease outbreaks (Ward et al 2019). Current detection measures in national biosecurity frameworks include some diagnostic techniques and provision of a notifiable list of wild, cultured and invasive fish pests and pathogens (PPRI No.…”