Intentional introductions of commercially harvested alien seaweeds
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Timothy D. Pickering
Abstract
The two main drivers for intentional introductions of commercial macroalgae are (1) increasing global demand for macroalgae and macroalgal products, and (2) increasing need for alternative and sustainable livelihoods among coastal communities in less-developed countries (particularly to reduce degradation of coral reefs) and in the less-developed rural areas of more-developed countries. The macroalgal species that form the basis for commercial aquaculture (mainly Saccharina japonica (J.E. Areschoug) C.E. Lane, C. Mayes, Druehl et G.W. Saunders, Porphyra species, Undaria pinnatifida, Kappaphycus alvarezii, and Gracilaria species) are thus the ones most likely to be intentionally introduced to other places. The highest-profile cases of “invasive” macroalgae have mainly resulted from unintentional introductions, particularly via shipping. Two cases are species important commercially for aquaculture, U. pinnatifida and K. alvarezii, although the global spread of U. pinnatifida beyond Asia has been caused mainly by shipping. K. alvarezii has been intentionally introduced to many countries for aquaculture and has been reported as invasive in one locality in Hawaii; however, more recently it has emerged that Eucheuma denticulatum is in fact the main culprit at this locality. While environmental problems from intentional introductions have been few compared with those from unintentional introductions, it does not appear that commercial species are, as a group, inherently any more or less risk-prone than most unintentionally introduced species. Only a minority of alien species may ever become invasive, but it is difficult to predict which will become pests. In principle, international norms allow states to intentionally introduce exotic species for commercial purposes, provided that environmental threats can be avoided. In practice, the burden of proof and duty of care about environmental threats and protection of biodiversity is nowadays much higher than before. States cannot take it for granted that alien species may be introduced; new proposals should follow formal risk assessment and monitoring processes that are science-based, and should be strongly justifiable in terms of ability to provide expected economic benefits.
©2007 by Walter de Gruyter Berlin New York
Articles in the same Issue
- Structure of this issue
- Is the cryptic alien seaweed Ulva pertusa (Ulvales, Chlorophyta) widely distributed along European Atlantic coasts?
- Daily timing of emersion and elevated atmospheric CO2 concentration affect photosynthetic performance of the intertidal macroalga Ulva lactuca (Chlorophyta) in sunlight
- Yucatán seaweeds from the offshore waters of Isla Mujeres, Quintana Roo, Mexico
- Dictyota dolabellana sp. nov. (Dictyotaceae, Phaeophyceae) based on morphological and chemical data
- Rostrupiella danica gen. et sp. nov., a Lulworthia-like marine lignicolous species from Denmark and the USA
- Ascoma development in the marine ascomycete Corollospora gracilis (Halosphaeriales, Hypocreomycetidae, Sordariomycetes)
- Low-molecular-mass carbohydrates and soluble polysaccharides of green and red morphs of Gracilaria domingensis (Gracilariales, Rhodophyta)
- Seaweed invasions: introduction and scope
- Introductions of seaweeds: accidental transfer pathways and mechanisms
- Intentional introductions of commercially harvested alien seaweeds
- Mechanisms of invasion: establishment, spread and persistence of introduced seaweed populations
- Mechanisms of invasions: can the recipient community influence invasion rates?
- Methods for identifying and tracking seaweed invasions
- Molecular approaches to the study of invasive seaweeds
- Impacts of introduced seaweeds
- Control of invasive seaweeds
- Invasive seaweeds: global and regional law and policy responses
- Seaweed invasions: conclusions and future directions
- Author information Special Issue Seaweed Invasions
- Subject index Special Issue Seaweed Invasions
- Reviewer acknowledgement Bot. Mar. volume 50 (2007)
- Contents index Bot. Mar. volume 50 (2007)
- Author index Bot. Mar. volume 50 (2007)
- Genus/Species index Bot. Mar. volume 50 (2007)
Articles in the same Issue
- Structure of this issue
- Is the cryptic alien seaweed Ulva pertusa (Ulvales, Chlorophyta) widely distributed along European Atlantic coasts?
- Daily timing of emersion and elevated atmospheric CO2 concentration affect photosynthetic performance of the intertidal macroalga Ulva lactuca (Chlorophyta) in sunlight
- Yucatán seaweeds from the offshore waters of Isla Mujeres, Quintana Roo, Mexico
- Dictyota dolabellana sp. nov. (Dictyotaceae, Phaeophyceae) based on morphological and chemical data
- Rostrupiella danica gen. et sp. nov., a Lulworthia-like marine lignicolous species from Denmark and the USA
- Ascoma development in the marine ascomycete Corollospora gracilis (Halosphaeriales, Hypocreomycetidae, Sordariomycetes)
- Low-molecular-mass carbohydrates and soluble polysaccharides of green and red morphs of Gracilaria domingensis (Gracilariales, Rhodophyta)
- Seaweed invasions: introduction and scope
- Introductions of seaweeds: accidental transfer pathways and mechanisms
- Intentional introductions of commercially harvested alien seaweeds
- Mechanisms of invasion: establishment, spread and persistence of introduced seaweed populations
- Mechanisms of invasions: can the recipient community influence invasion rates?
- Methods for identifying and tracking seaweed invasions
- Molecular approaches to the study of invasive seaweeds
- Impacts of introduced seaweeds
- Control of invasive seaweeds
- Invasive seaweeds: global and regional law and policy responses
- Seaweed invasions: conclusions and future directions
- Author information Special Issue Seaweed Invasions
- Subject index Special Issue Seaweed Invasions
- Reviewer acknowledgement Bot. Mar. volume 50 (2007)
- Contents index Bot. Mar. volume 50 (2007)
- Author index Bot. Mar. volume 50 (2007)
- Genus/Species index Bot. Mar. volume 50 (2007)
