PERTH'S Swan River is alive and generally well despite reports to the contrary, scientists say.
Researcher Chris Hallett says a new report by Murdoch University counters recent media suggestions the Swan-Canning Estuary is "dead".
Dr Hallett said the condition of the estuary remained "generally good to fair".
"The results are consistent with our previous monitoring, which has indicated an overall improvement in the ecological condition of the Swan-Canning Estuary since the mid 2000s," he said.
A Fish Community Index was used to rate the health of the estuary from A (very good) to E (very poor), compared to data collected over 30 years.
The Swan River Trust established an annual monitoring program using the index.
Scientists sampled and assessed more than 30,000 fish from 40 species at 48 locations during the first half of this year.
While the health of upper Swan and Canning estuary habitats was considered slightly poorer at times, compared to the 2012 data, it was attributed to the presence of low oxygen conditions in the deeper waters of the upper estuary zones during autumn this year.
Dr Hallett said the events had a short-term impact on the estuaries.
"Trends over the last five to eight years show that the system is fairly resilient to the algal blooms and low oxygen events that periodically affect parts of the estuary," he said.
"Our research indicates that the majority of fish species are able to avoid low oxygen areas by moving closer to shore, where oxygen levels are higher.
"The fish tend to return to deeper waters when oxygen levels return to normal."
This behaviour had been credited with reducing the extent of fish kills following a major algal bloom in the Swan-Canning Estuary in 2004, Dr Hallett said.
Anda sedang membaca artikel tentang
Swan River not dead, say Perth scientists
Dengan url
http://beritasementara.blogspot.com/2013/11/swan-river-not-dead-say-perth-scientists.html
Anda boleh menyebar luaskannya atau mengcopy paste-nya
Swan River not dead, say Perth scientists
namun jangan lupa untuk meletakkan link
Swan River not dead, say Perth scientists
sebagai sumbernya
0 komentar:
Posting Komentar