Predicting New Zealand riverine fish reference assemblages

PeerJ

article

Adam D. Canning¹ 

[1] Wellington Fish and Game Council

关键词: Ecosystem health;    Fish barriers;    Observed/expected;    Nutrients;    Riparian;    Exotic fish;    Biomonitoring;    New Zealand;    Freshwater;    Fish community;   

DOI  :  10.7717/peerj.4890

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

Biomonitoring is a common method to monitor environmental change in river ecosystems, a key advantage of biomonitoring over snap-shot physicochemical monitoring is that it provides a more stable, long-term insight into change that is also effects-based. In New Zealand, the main biomonitoring method is a macroinvertebrate sensitivity scoring index, with little established methods available for biomonitoring of fish. This study models the contemporary distribution of common freshwater fish and then uses those models to predict freshwater fish assemblages for each river reach under reference conditions. Comparison of current fish assemblages with those predicted in reference conditions (as observed/expected (O/E) ratios) may provide a suitable option for freshwater fish biomonitoring. Most of the fish communities throughout the central North Island and lower reaches show substantial deviation from the modelled reference community. Most of this deviation is explained by nutrient enrichment, followed by downstream barriers (i.e. dams) and loss of riparian vegetation. The presence of modelled introduced species had relatively little impact on the presence of the modelled native fish. The maps of O/E fish assemblage may provide a rapid way to identify potential restoration sites.

【 授权许可】

CC BY