Detecting anthropogenic disturbance in an environment with multiple gradients of physical disturbance, Manukau Harbour, New Zealand

2000 ◽  
pp. 379-391
Author(s):  
J. I. Ellis ◽  
D. C. Schneider ◽  
S. F. Thrush
Keyword(s):  
New Zealand ◽  
Anthropogenic Disturbance ◽  
Physical Disturbance

scholarly journals Sediment impacts on sponges and a deep-sea coral in New Zealand

2021 ◽  
Author(s):  
◽  
Valeria Mobilia
Keyword(s):  
New Zealand ◽  
Suspended Sediment ◽  
Deep Sea ◽  
Anthropogenic Disturbance ◽  
Habitat Structure ◽  
Anthropogenic Activities ◽  
Benthic Communities ◽  
Bottom Contact ◽  
Suspended Sediment Concentrations ◽  
Offshore Activities

<p><b>Increased levels of suspended sediment in the water column are important factors contributing to the degradation of marine ecosystems worldwide. In coastal waters, temporal variation in suspended sediment concentrations (SSCs) occurs naturally due to seasonal and oceanographic processes. However, there is evidence that anthropogenic activities are increasing sediment concentrations. The volume of sediment moving from land-based sources into coastal ecosystems and human activities in the ocean disturbing the seafloor, such as dredging and bottom-contact fisheries, have been increasing over the last century. In addition, offshore activities, particularly bottom-contact fishing and potential deep-sea mining, can create sediment plumes in the deep-sea that may extend over long distances. Elevated suspended sediment concentrations have detrimental effects on benthic communities, particularly for suspension feeders like sponges and corals.</b></p> <p>The aim of this thesis was to investigate the effects of increased SSCs that might arise from heavy anthropogenic disturbance on common shallow water and deep-sea sponges and a deep-sea coral in New Zealand, as these groups contribute to habitat structure in some benthic environments, including the deep sea.</p>

scholarly journals Effects of mangrove removal on benthic communities and sediment characteristics at Mangawhai Harbour, northern New Zealand

2010 ◽  
Vol 67 (6) ◽  
pp. 1087-1104 ◽  
Author(s):  
Andrea C. Alfaro
Keyword(s):  
New Zealand ◽  
Anthropogenic Disturbance ◽  
Forest Decline ◽  
Benthic Communities ◽  
Organic Content ◽  
Sediment Characteristics ◽  
Subsequent Increase ◽  
Before And After ◽  
Faunal Density ◽  
The Tropics

Abstract Alfaro, A. C. 2010. Effects of mangrove removal on benthic communities and sediment characteristics at Mangawhai Harbour, northern New Zealand. – ICES Journal of Marine Science, 67: 1087–1104. The spread of mangroves at many locations in temperate northern New Zealand provides a stark contrast to the well-documented trend in mangrove forest decline recorded through the tropics and subtropics. To explore this difference, improved understanding is needed of New Zealand's mangrove ecosystems and how they respond to anthropogenic disturbance. The effect of mangrove removal on the community ecology of mangrove stands and adjacent habitats was investigated within Mangawhai Estuary, northern New Zealand, between March 2004 and September 2006. The vegetation, benthic macrofauna, and sediments were sampled within habitats (marshgrass, mangrove stands, pneumatophore zones, sandflats, and channels) at a treatment site (mangroves removed) and two undisturbed sites, before and after mangrove-removal activities. Mature mangrove habitats had less total abundance and fewer taxa than all the other habitats sampled and were dominated by pulmonate snails (Amphibola crenata) and mud crabs (Helice crassa). Whereas faunal composition varied seasonally as a result of life-history dynamics, temporal changes could be attributed to mangrove-removal activities. Mangrove eradication was followed by immediate changes in the sediment from a muddy to sandier environment, which favoured an overall increase in the abundance of crabs, snails, and bivalves. However, unexpected topographic catchment reconfigurations in late 2005 may have caused a subsequent increase in the delivery of silt and organic content to the study area and an overall decrease in faunal density in March and September 2006. The study provides direct evidence of the effect of mangroves on sediment and benthic faunal characteristics and the importance of catchment-derived imports to estuarine ecosystems.

scholarly journals Sediment impacts on sponges and a deep-sea coral in New Zealand

2021 ◽  
Author(s):  
◽  
Valeria Mobilia
Keyword(s):  
New Zealand ◽  
Suspended Sediment ◽  
Deep Sea ◽  
Anthropogenic Disturbance ◽  
Habitat Structure ◽  
Anthropogenic Activities ◽  
Benthic Communities ◽  
Bottom Contact ◽  
Suspended Sediment Concentrations ◽  
Offshore Activities

<p><b>Increased levels of suspended sediment in the water column are important factors contributing to the degradation of marine ecosystems worldwide. In coastal waters, temporal variation in suspended sediment concentrations (SSCs) occurs naturally due to seasonal and oceanographic processes. However, there is evidence that anthropogenic activities are increasing sediment concentrations. The volume of sediment moving from land-based sources into coastal ecosystems and human activities in the ocean disturbing the seafloor, such as dredging and bottom-contact fisheries, have been increasing over the last century. In addition, offshore activities, particularly bottom-contact fishing and potential deep-sea mining, can create sediment plumes in the deep-sea that may extend over long distances. Elevated suspended sediment concentrations have detrimental effects on benthic communities, particularly for suspension feeders like sponges and corals.</b></p> <p>The aim of this thesis was to investigate the effects of increased SSCs that might arise from heavy anthropogenic disturbance on common shallow water and deep-sea sponges and a deep-sea coral in New Zealand, as these groups contribute to habitat structure in some benthic environments, including the deep sea.</p>

Sign in / Sign up

Export Citation Format

Share Document