Sediment remobilisation from decomposing cordgrass (Spartina anglica) patches on a wave‐exposed intertidal flat

Swales, Andrew; Ovenden, Ron; MacDonald, Iain T.; Lohrer, Andrew M.; Burt, Karen L.

doi:10.1080/00288330.2005.9517395

“…Plant competition can be affected not only by resource availability 10 , but also by environmental factors within a salt marsh 4 11 12 13 , such as sediment 9 14 15 , sea level 4 5 and salinity 7 16 . It has been shown that competition between species, especially between exotic and native species, often depend on nutrient supply 9 17 18 , flooding 19 , elevation 4 and other factors 20 .…”

mentioning

confidence: 99%

“…Salt marsh sediments are mainly influenced by plant activity, elevation and tidal flooding 14 22 23 24 25 . Because much of the organic matter in tidal flooding originates from external sources or from benthic microalgae, sediments are usually rich in organic matter and phosphorus 26 27 28 .…”

mentioning

confidence: 99%

Sediment Type Affects Competition between a Native and an Exotic Species in Coastal China

Liu

¹

,

Wang

²

,

An

³

et al. 2014

Sci Rep

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Different types of sediments in salt marsh have different physical and chemical characters. Thus sediment type plays a role in plant competition and growth in salt marsh ecosystems. Spartina anglica populations have been increasingly confined to upper elevation gradients of clay, and the niche sediment has changed. Because the niches of S. anglica and the native species Scirpus triqueter overlap, we conducted a greenhouse experiment to test the hypothesis that plant competition has changed under different types of sediments. Biomass and asexual reproduction were analyzed, and inter- and intraspecific competition was measured by log response ratio for the two species in both monoculture and combination under three sediment types (sand, clay and mixture of sand and clay). For S. anglica, biomass, ramet number and rhizome length in combination declined significantly compared with those in monoculture, and the intensity of interspecific competition was significantly higher than that of intraspecific competition under all sediments. For S. triqueter, the intensities of intra- and interspecific competition were not significantly different. This indicates that S. triqueter exerts an asymmetric competitive advantage over S. anglica across all sediments, but especially clay. Thus the sediment type changes competition between S. anglica and S. triqueter.

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“…A number of marine introductions to New Zealand have been intentional, such as the saltmarsh cordgrass Spartina spp. (Swales et al 2005), which was originally introduced for its perceived beneficial role in reclaiming and stabilizing tidal flats in estuaries.…”

Section: Marine Biosecurity In New Zealandmentioning

confidence: 99%

“…Allen and Lee 2006), might also be feasible in the marine environment?A recent synthesis of biological invasions in New Zealand byAllen and Lee (2006) provides a number of examples where the efficacy of post-border pest management in terrestrial and freshwater systems has been demonstrated. These include successes in the restoration and recovery of native vegetation through control of introduced herbivores such as rabbits, goats and deer(Coomes et al 2006), control programmes for non-indigenous predators (e.g., stoats, rats) of native birds or their eggs(McLennan 2006), and spraying programmes for invasive aquatic and terrestrial weeds (e.g.,Swales et al 2005). Among the more high profile recent examples have been the use of 1080 poison to control possum populations, trials with copper-based agents to control 'Didymo' in rivers, and a successful eradication of the painted apple moth in Auckland through an aerial spraying campaign.…”

mentioning

confidence: 99%

Managing Risks from Invasive Marine Species: Is Post-Border Management Feasible?

Forrest¹

1

0

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Non-indigenous marine species are a major threat to marine environments and economies globally. This thesis examines whether management of pest organisms post-border (i.e, after they have established in New Zealand) is feasible in the marine environment, using the non-indigenous Asian kelp Undaria pinnatifida as a model organism. Background information on Undaria in Chapter 2 recognises the paucity of information on Undaria's impacts. Hence, Chapter 3 investigates ecological effects from Undaria in a low shore rocky habitat. Although negligible effects were described, the uncertainty in extrapolating findings to other places and times means that the precautionary principle should be applied by managers, and 'worst-case' impacts assumed. Chapter 4 investigates mechanisms for Undaria's natural dispersal, and describes strategies based on spore release and sporophyte drift that may lead to spread over scales of metres to kilometres. This work highlights the importance of human transport vectors (especially vessels and aquaculture) in the post-border spread of Undaria at regional and national scales. Hence, a case study in Chapter 5 describes aquaculture activities that could be vectors for spread of Undaria in New Zealand, and presents criteria for identifying present and future high risk pathways. Chapters 6 and 7 describe methods to reduce the accidental transport of Undaria and other biofouling pests with aquaculture, with a focus on mussel farming. Treatments based on water blasting, air drying and freshwater immersion provide low cost options for equipment such as floats and rope. For treatment of mussel seed-stock, immersion in dilute (4%) acetic acid (the active ingredient in vinegar) is identified as a method that could eliminate Undaria and other soft-bodied fouling organisms without resulting in an unacceptable level of mussel mortality. Chapter 8 proposes a risk-based framework for setting post-border management priorities based on the feasibility, benefits and costs of risk reduction. This chapter elucidates how knowledge generated from research in Chapters 2-7 can be used in a biosecurity risk management context. It shows that effective management post-border is possible even when pest organisms become relatively well established, and that the benefits gained from even limited successes have the potential to greatly outweigh the consequences of uncontrolled invasion. However, as unwanted species become increasingly widespread, management will become increasingly focussed on the protection of specific values. Chapter 9 extends some of the ideas proposed in Chapter 8, and considers a broad postborder management framework for marine pests. A comprehensive system should consist of vector management, surveillance, and incursion response that targets particular pests or suites of functionally similar species (e.g., biofouling organisms), coupled with generic vector management approaches that aim to reduce humanmediated transport of all organisms at a national scale. New Zealand's geographic isolation and low population, hence relatively low level of vector activity, makes the management of human-mediated pathways of spread entirely feasible in many circumstances. Hence, while there are clearly many challenges in the post-border management of marine pests, this is nonetheless a realistic goal, and probably moreso in New Zealand than in any other country in the world.

show abstract

“…A number of marine introductions to New Zealand have been intentional, such as the saltmarsh cordgrass Spartina spp. (Swales et al 2005), which was originally introduced for its perceived beneficial role in reclaiming and stabilizing tidal flats in estuaries.…”

Section: Marine Biosecurity In New Zealandmentioning

confidence: 99%

Managing Risks from Invasive Marine Species: Is Post-Border Management Feasible?

Forrest¹

0

View full text Add to dashboard Cite

Non-indigenous marine species are a major threat to marine environments and economies globally. This thesis examines whether management of pest organisms post-border (i.e, after they have established in New Zealand) is feasible in the marine environment, using the non-indigenous Asian kelp Undaria pinnatifida as a model organism. Background information on Undaria in Chapter 2 recognises the paucity of information on Undaria's impacts. Hence, Chapter 3 investigates ecological effects from Undaria in a low shore rocky habitat. Although negligible effects were described, the uncertainty in extrapolating findings to other places and times means that the precautionary principle should be applied by managers, and 'worst-case' impacts assumed. Chapter 4 investigates mechanisms for Undaria's natural dispersal, and describes strategies based on spore release and sporophyte drift that may lead to spread over scales of metres to kilometres. This work highlights the importance of human transport vectors (especially vessels and aquaculture) in the post-border spread of Undaria at regional and national scales. Hence, a case study in Chapter 5 describes aquaculture activities that could be vectors for spread of Undaria in New Zealand, and presents criteria for identifying present and future high risk pathways. Chapters 6 and 7 describe methods to reduce the accidental transport of Undaria and other biofouling pests with aquaculture, with a focus on mussel farming. Treatments based on water blasting, air drying and freshwater immersion provide low cost options for equipment such as floats and rope. For treatment of mussel seed-stock, immersion in dilute (4%) acetic acid (the active ingredient in vinegar) is identified as a method that could eliminate Undaria and other soft-bodied fouling organisms without resulting in an unacceptable level of mussel mortality. Chapter 8 proposes a risk-based framework for setting post-border management priorities based on the feasibility, benefits and costs of risk reduction. This chapter elucidates how knowledge generated from research in Chapters 2-7 can be used in a biosecurity risk management context. It shows that effective management post-border is possible even when pest organisms become relatively well established, and that the benefits gained from even limited successes have the potential to greatly outweigh the consequences of uncontrolled invasion. However, as unwanted species become increasingly widespread, management will become increasingly focussed on the protection of specific values. Chapter 9 extends some of the ideas proposed in Chapter 8, and considers a broad postborder management framework for marine pests. A comprehensive system should consist of vector management, surveillance, and incursion response that targets particular pests or suites of functionally similar species (e.g., biofouling organisms), coupled with generic vector management approaches that aim to reduce humanmediated transport of all organisms at a national scale. New Zealand's geographic isolation and low population, hence relatively low level of vector activity, makes the management of human-mediated pathways of spread entirely feasible in many circumstances. Hence, while there are clearly many challenges in the post-border management of marine pests, this is nonetheless a realistic goal, and probably moreso in New Zealand than in any other country in the world.

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Sediment remobilisation from decomposing cordgrass (Spartina anglica) patches on a wave‐exposed intertidal flat

Cited by 5 publications

References 33 publications

Sediment Type Affects Competition between a Native and an Exotic Species in Coastal China

Sediment Type Affects Competition between a Native and an Exotic Species in Coastal China

Managing Risks from Invasive Marine Species: Is Post-Border Management Feasible?

Managing Risks from Invasive Marine Species: Is Post-Border Management Feasible?

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