Differential effects of suspended sediments on larval survival and settlement of New Zealand urchins Evechinus chloroticus and abalone Haliotis iris

10.26686/wgtn.13012997 ◽

2020 ◽

Author(s):

Nicole Phillips ◽

Jeffrey Shima

Keyword(s):

New Zealand ◽

Life History Traits ◽

Sea Urchins ◽

Suspended Sediments ◽

Mortality Rates ◽

Larval Survival ◽

Larval Connectivity ◽

Species Specific ◽

Timing Of Exposure ◽

Dynamics Of Populations

Larvae of marine organisms play an important role in the dynamics of populations, are generally sensitive to environmental stressors, and vary dramatically among species in life history traits. We examined the effects of suspended sediments from terrestrial runoff on larval development, survival, and settlement of New Zealand sea urchins Evechinus chloroticus and abalone Haliotis iris. Larval urchins and abalone were reared under 5 suspended sediment regimes (variable concentrations and timing of exposure, benchmarked against nearby field conditions), and in the absence of sediments. Stage specific per capita mortality rates of urchin larvae increased with concentrations of suspended sediments, and generally, these rates (and the sensitivity of urchin larvae to sediments) decreased with age. Mortality rates of abalone similarly increased in response to sediment concentrations, although older larvae continued to incur high losses when exposed to sediments. Mortality rates of both abalone and urchins increased in response to acute exposure to sediments early in development. For urchins, this effect was immediate and coincident only with exposure to sediments, whereas elevated mortality rates persisted well after the removal of sediments for abalone. Cumulative survival to competency was similar among species and generally decreased with exposure time and/or concentration of sediments. Urchins were twice as likely to settle and metamorphose as abalone but patterns were not related to larval sediment regime for either species. The strong species specific responses to suspended sediments we observe may greatly alter patterns of larval connectivity in marine meta-communities. © Inter-Research 2006.

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Differential effects of suspended sediments on larval survival and settlement of New Zealand urchins Evechinus chloroticus and abalone Haliotis iris

10.26686/wgtn.13012997.v1 ◽

2020 ◽

Author(s):

Nicole Phillips ◽

Jeffrey Shima

Keyword(s):

New Zealand ◽

Life History Traits ◽

Sea Urchins ◽

Suspended Sediments ◽

Mortality Rates ◽

Larval Survival ◽

Larval Connectivity ◽

Species Specific ◽

Timing Of Exposure ◽

Dynamics Of Populations

Larvae of marine organisms play an important role in the dynamics of populations, are generally sensitive to environmental stressors, and vary dramatically among species in life history traits. We examined the effects of suspended sediments from terrestrial runoff on larval development, survival, and settlement of New Zealand sea urchins Evechinus chloroticus and abalone Haliotis iris. Larval urchins and abalone were reared under 5 suspended sediment regimes (variable concentrations and timing of exposure, benchmarked against nearby field conditions), and in the absence of sediments. Stage specific per capita mortality rates of urchin larvae increased with concentrations of suspended sediments, and generally, these rates (and the sensitivity of urchin larvae to sediments) decreased with age. Mortality rates of abalone similarly increased in response to sediment concentrations, although older larvae continued to incur high losses when exposed to sediments. Mortality rates of both abalone and urchins increased in response to acute exposure to sediments early in development. For urchins, this effect was immediate and coincident only with exposure to sediments, whereas elevated mortality rates persisted well after the removal of sediments for abalone. Cumulative survival to competency was similar among species and generally decreased with exposure time and/or concentration of sediments. Urchins were twice as likely to settle and metamorphose as abalone but patterns were not related to larval sediment regime for either species. The strong species specific responses to suspended sediments we observe may greatly alter patterns of larval connectivity in marine meta-communities. © Inter-Research 2006.

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The Effect of Suspended Sediment Loads on the Growth, Oxygen Consumption and Mucus Production of Pāua (Haliotis iris)

10.26686/wgtn.17142830.v1 ◽

2021 ◽

Author(s):

◽

Taputukura Raea

Keyword(s):

Oxygen Consumption ◽

New Zealand ◽

Suspended Sediment ◽

Marine Environment ◽

Large Scale ◽

Suspended Sediments ◽

Urban Land Use ◽

Foraging Efficiency ◽

Mucus Production ◽

Sediment Loads

<p>Land based-effects, including sedimentation are threatening estuarine and coastal systems globally. Ecological systems are faced with significant pressures from human activities including toxic pollution, eutrophication, habitat fragmentation and sedimentation. In recent years sediment inputs into marine systems have been greatly accelerated through land-based activities such as urban-land use, agriculture, coastal developments, large scale land clearances and farming. Effects of sedimentation on marine organisms include suffocation, reduced foraging efficiency and clogging of the gills of filter feeders. In New Zealand, sedimentation is the most important land-based stressor on the coastal marine environment. The pāua (Haliotis iris), is an important macroalgal grazer and is one of New Zealand’s top 10 seafood exports. However, little is known about the effects suspended sediments have on H. iris. The aim of this thesis is to experimentally test the effects of suspended sediment on the growth, oxygen consumption and mucus production for H. iris, using sediment concentrations that would naturally occur within Wellington Harbour, New Zealand. Suspended sediment had no significant effect on H. iris growth or oxygen consumption. However, exposure to suspended sediments significantly reduced mucus production in H. iris. There were also trends in the data to suggest that respiration in smaller H. iris was reduced by suspended sediments. Limited studies have explored the effect of suspended sediments on gastropods, even though sedimentation is one of the most significant land based stressors on the marine environment, not only in New Zealand, but also worldwide. This study has led to a better understanding of the potential implications suspended sediment may incur for not only H. iris, but also Haliotis species in general.</p>

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Short-Term Effects of High Suspended Sediments on Six Common New Zealand Stream Invertebrates

Hydrobiologia ◽

10.1007/s10750-005-4167-5 ◽

2005 ◽

Vol 548 (1) ◽

pp. 67-74 ◽

Cited By ~ 19

Author(s):

Alastair M. Suren ◽

Michael L. Martin ◽

Brian J. Smith

Keyword(s):

New Zealand ◽

Suspended Sediments ◽

Short Term ◽

Stream Invertebrates ◽

Short Term Effects

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The Effect of Suspended Sediment Loads on the Growth, Oxygen Consumption and Mucus Production of Pāua (Haliotis iris)

10.26686/wgtn.17142830 ◽

2021 ◽

Author(s):

◽

Taputukura Raea

Keyword(s):

Oxygen Consumption ◽

New Zealand ◽

Suspended Sediment ◽

Marine Environment ◽

Large Scale ◽

Suspended Sediments ◽

Urban Land Use ◽

Foraging Efficiency ◽

Mucus Production ◽

Sediment Loads

<p>Land based-effects, including sedimentation are threatening estuarine and coastal systems globally. Ecological systems are faced with significant pressures from human activities including toxic pollution, eutrophication, habitat fragmentation and sedimentation. In recent years sediment inputs into marine systems have been greatly accelerated through land-based activities such as urban-land use, agriculture, coastal developments, large scale land clearances and farming. Effects of sedimentation on marine organisms include suffocation, reduced foraging efficiency and clogging of the gills of filter feeders. In New Zealand, sedimentation is the most important land-based stressor on the coastal marine environment. The pāua (Haliotis iris), is an important macroalgal grazer and is one of New Zealand’s top 10 seafood exports. However, little is known about the effects suspended sediments have on H. iris. The aim of this thesis is to experimentally test the effects of suspended sediment on the growth, oxygen consumption and mucus production for H. iris, using sediment concentrations that would naturally occur within Wellington Harbour, New Zealand. Suspended sediment had no significant effect on H. iris growth or oxygen consumption. However, exposure to suspended sediments significantly reduced mucus production in H. iris. There were also trends in the data to suggest that respiration in smaller H. iris was reduced by suspended sediments. Limited studies have explored the effect of suspended sediments on gastropods, even though sedimentation is one of the most significant land based stressors on the marine environment, not only in New Zealand, but also worldwide. This study has led to a better understanding of the potential implications suspended sediment may incur for not only H. iris, but also Haliotis species in general.</p>

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Argentine stem weevil (Listronotus bonariensis, Coleoptera: Curculionidae) population dynamics in Canterbury, New Zealand dryland pasture

Bulletin of Entomological Research ◽

10.1017/s0007485310000507 ◽

2010 ◽

Vol 101 (3) ◽

pp. 295-303 ◽

Cited By ~ 9

Author(s):

S.L. Goldson ◽

M.C. Barron ◽

J.M. Kean ◽

C. van Koten

Keyword(s):

Population Dynamics ◽

New Zealand ◽

Population Analysis ◽

Larval Survival ◽

Compensatory Response ◽

The North ◽

Key Factor ◽

Listronotus Bonariensis ◽

Pupal Mortality ◽

Microctonus Hyperodae

AbstractThe Argentine stem weevil (Listronotus bonariensis) was an economically important pest in New Zealand pastures until the release of the parasitoidMicroctonus hyperodae. This contribution uses historical data to investigate the regulation of the pest populations prior to, and somewhat during, the establishment of this parasitoid in dryland Canterbury, New Zealand. Thus, a significant goal of this study is to provide anL. bonariensispopulation dynamics baseline for any future work that aims to analyse the full effects ofM. hyperodaeon the weevil, now that equilibrium with the weevil host has been reached.The population dynamics ofL. bonariensis, based on a life-table approach, were investigated using data collected regularly for eight years from populations in Canterbury, New Zealand. The key factor affecting end-of-seasonL. bonariensisdensity was found to be variation in second generation fourth instar prepupal and pupal mortality. This may have been caused by arrested development and ongoing mortality resulting from the onset of cooler autumnal conditions.A compensatory response was found in recruitment to the second summer weevil generation, whereby the realised fecundity of the emergent first summer generation of weevils was found to be negatively related to the density of adult weevils per ryegrass tiller. This is the first time that this has been found via long-term population analysis ofL. bonariensis, although indications of this have been found elsewhere in caging, pot and small plot experiments.In this study, the effect of the parasitoid biocontrol agentMicroctonus hyperodaeonL. bonariensispopulation dynamics was unclear, as the analysis covered a period when the parasitoidMicroctonus hyperodaewas introduced and still establishing. It does, however, raise important questions for future analysis in terms of the interaction between parasitism and unrealised fecundity.The results in this contribution also highlighted regional differences. Overwintering mortality of adult weevils in Canterbury was constant between years, whilst earlier studies in the North Island Waikato region indicated this mortality was density dependent. In addition, the availability of tillers in endophyte-free ryegrass pastures in Canterbury had no influence on egg and early-instar larval survival, which contrasts with the finding from endophytic Waikato pastures.

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