Cape Natures Proposal To Poison Rivers

[croozer]

Thanks Morne . good read.

[rols]

Sorry, I posted it in the wrong thread earlier.....

I read Andrew Levy's article in the October TCFF this morning and thought I'd mention it as it's very thought provoking, as well as very real and sums up the sometimes unwarranted actions or lack thereof, by the powers that be. It's in his usual spot at the rear of the magazine. Simplifies it beautifully, but leaves you thinking. Worth a read.

[turando101]

Hi all,
Not sure if this link has been posted here before. It was recently posted on a fishkeeping list that I belong to. Basically if you go through it you will find that rainbow and brown trout will be legal to import into SA. In addition they and 3 types of bass (largemouth, smallmouth and spotted) are rated as "Zoned for acceptable known introduced distribution by provincial authorities" which it seems is interpreted as they will be allowed to stay where they are (in general).
http://www.sanbi.org/frames/whatsnewcurfram.htm
You can also send inputs to the compilers of the list.
Kind regards,
KarelM

[BuzzLiteBeer]

Melanie Gosling
January 22 2009 at 07:18AM


CapeNature could use the controversial fish poison Rotenone to kill alien fish in four selected rivers without significant harm to the river or land ecosystem.

This was the finding of the environmental impact assessment (EIA) released on Wednesday for public comment. The proposal has yet to be approved by the authorities.

The proposed use of Rotenone has caused widespread alarm because uncontrolled use in the past has led to serious ecological harm to river systems, with high doses of the poison killing off almost everything in the water.

But the specialist studies have found that if used in a controlled manner in low doses according to an approved environmental management plan, the poison would be an acceptable way of getting rid of alien fish, chiefly trout and bass.

The report says if no action is taken to eradicate alien fish, some species of indigenous fish in the Cape Floral Region will become extinct.

It says Rotenone, a natural poison from the root of a South American tree, has been used "widely and successfully" on a much greater scale than that proposed by CapeNature.

The specialists found using nets or electric fishing to get rid of alien fish would work only in the upper section of the Krom in the Cederberg.

Where this would not be feasible, the only means of ensuring the complete removal of alien fish would be the use of fish poison.

The poison will also kill all indigenous fish and some of the macroinvertebrates like dragonflies, mayflies and beetles.

The time the river takes to recover will depend on whether it can be repopulated naturally or artificially, or by removing organisms and storing them.

The poison would have a "negligible" impact on land ecology, the report said, and different macroinvertebrates had widely differing tolerances of Rotenone, so the severity of harm would vary greatly between species.

The poison would affect some species of frogs and tadpoles, none of them threatened.

The rivers where sections would be poisoned are the Suurvlei, Rondegat and Krom in the Cederberg and the Krom in the Eastern Cape.

Water birds, otters and snakes in these four rivers are not likely to be affected as they "lack an effective mechanism for transporting Rotenone into the bloodstream", and can tolerate doses several times higher than those used to kill fish.

The report recommends that some indigenous fish be caught and kept in pools before the poison is used.

The EIA, with public comment, is to be submitted to the authorities next month.

This article was originally published on page 3 of Cape Times on January 22, 2009

[CTHOMAS]

Once again this journalist talks as if there has been a test run to establish the real effects of a real poisoning.If they have done this ,where was it done and why no publicity or communication? What has happened to Canal walk in the meantime since its clean out? Is there a research project on it by some university perhaps? It might placate the panic. Mind you,if you see what goes into our rivers locally maybe Rotenone etc. might be ok!
I would like to know.

[Chris Shelton]

I received the following 2 days ago

Dear I&APs.
DRAFT ENVIRONMENTAL IMPACT REPORT &
ENVIRONMENTAL MANAGEMENT PLAN
20th JANUARY 2009
ENVIRONMENTAL IMPACT ASSESSMENT OF THE PROPOSED
ERADICATION OF INVASIVE ALIEN FISHES FROM SELECTED RIVERS IN
THE CAPE FLORISTIC REGION
In October 2008 the Final Scoping Report of this EIA was made available on the EFA
website, http://www.envirofishafrica.co.za/projects.php?path .
The main issues arising from the draft report were questions as to the legal aspects
surrounding the project. It was emphasised that for future alien eradication programmes
proper protocols must be put in place in South Africa. As a result of this, the conservation
authorities approved a proposal by EFA to seek further legal opinion, and this legal
review is now underway. In addition, as a result of the recommendations made in the
scoping phase, CapeNature has developed a detailed planning programme for overall
alien invasive management.
These activities are conducted in addition to the EIA for which the next phase is the
completion of two further draft documents, which are now available on the EFA website,
http://www.envirofishafrica.co.za/projects.php?path. The documents are contained in a
folder named ‘Draft EIR and EMP (20th January 2009)’. These documents are being
made available for comment by IAPs and the relevant conservation authorities until 20th
February 2009.
The first document is the DRAFT Environmental Impact Report, which assesses and
quantifies the likely impacts on the environment in the short, medium and long term, and
which incorporates reports on the specialist studies recommended in the scoping phase.
The second document is the DRAFT Environmental Management Plan, which spells out
the steps to be taken during the implementation of the proposed project to ensure it is
carried out effectively and to mitigate the likely environmental impacts. There will now
be an opportunity for further public participation following the publication of these draft
documents.
Comments are invited on the documents and public meetings will be advertised and held
in mid February 2009. The dates will be advertised in the newspapers and you will also
be informed by email in due course.
Comments should be made in writing before the 20th February 2009 and either sent to the
Project Coordinator, Mr Tweddle by email (d.tweddle@saiab.ac.za), by fax at 046
6227950, or by mail to 22 Somerset Street, Grahamstown, 6139.
Yours faithfully.
Denis Tweddle
EFA, EIA Project Coordinator
Enviro-Fish Africa (Pty) Ltd
22 Somerset Street
Grahamstown 6139
d.tweddle@saiab.ac.za
Please copy all email correspondence to efa@ru.ac.za

[JamesW]

The three rivers to be targeted for alien fish eradication and justification therefor are as follows;

Suurvlei River, Cederberg

The Twee River redfin, Barbus erubescens, is restricted to the Twee River system and is critically endangered. In the last 10 years this species has disappeared from the Suurvlei tributary with the exception of a pool below a waterfall at the head of the stretch of 5 km previously occupied by B. erubescens. The loss of B. erubescens is primarily blamed on the escape of introduced cape kurper, Sandelia capensis, from a broken dam above the affected stretch of the Suurvlei. Elsewhere in the Twee River system, introduced American bluegill sunfish, Lepomis macrochirus, and Clanwilliam yellowfish, Labeobarbus capensis, also threaten Barbus erubescens as well as a Twee River endemic Galaxias sp. While alien fishes are not the only problem in the Suurvlei and the rest of the Twee River system, eradicating them will be of major benefit to the redfin.

The stretch proposed for alien eradication in the Suurvlei River is from the upper limit of alien invasion for 5 km downstream to a weir to be constructed at or near the Suikerbossie road bridge


Rondegat River, Cederberg

The upper reaches of the Rondegat River, which flows directly into Clanwilliam Reservoir supports thriving populations of five indigenous fish species, fiery redfin, Pseudobarbus phlegethon, Clanwilliam redfin, Barbus calidus, Clanwilliam yellowfish, Labeobarbus capensis, Clanwilliam rock catfish, Austroglanis gilli and the Olifants system endemic Galaxias sp. This stretch of river (~20 km) terminates in a small waterfall below which the fish population is dominated by American smallmouth bass, Micropterus dolomieu and bluegill. Adult yellowfish are also in evidence in the pools below the waterfall, but no juvenile yellowfish or any redfins. The stretch of this upper catchment river holding indigenous fishes is short and vulnerable, and the stretch of river downstream of the waterfall contains numerous pools that are larger than those found in the present indigenous species zone upstream and form ideal habitat for the indigenous species. Removing alien fishes downstream of the waterfall to another barrier (an existing water offtake weir near Clanwilliam Reservoir for a fruit farm on the shores of the reservoir) will add approximately 4 km (an extra 20% in length) of habitat for the indigenous species, greatly enhancing their survival prospects.

Krom River, Cederberg

The Krom River arises in the Cederberg and flows for about 8 km down a steep-sided valley before levelling off into the Kromrivier farmland, from which it flows for another 10 km to enter the Matjies River. At present the only indigenous fish species in the river is Austroglanis gilli, the distribution of which extends for a few hundred metres above the farm. It is almost certain that the Krom River was formerly populated by redfins, specifically the Doring River strain of Pseudobarbus phlegethon. The fast-flowing stream in the valley is invaded by rainbow trout, Onchorhynchus mykiss, up to the Disas Pool below a substantial waterfall that forms an effective barrier to upstream fish movement. The farm dams contain American bass species and from the farm downstream the river is also invaded by bass and bluegill. By eradicating the alien fishes from the river it will create extensive habitat for the reintroduction of Pseudobarbus phlegethon using the Doring River strain either from the adjacent Breekkrans tributary or the Doring River. There is also an option to reintroduce other fish species under threat that are native to the Doring River, i.e. Barbus calidus, Labeobarbus capensis and the Clanwilliam sawfin, Barbus serra.

The stretch proposed for alien eradication is the 18 km stretch from Disas Pool at the head of trout distribution down to a weir just above the confluence with the Matjies River.

Has this happened yet? Heading to the Kromriver nature reserve this weekend... are there any fishing opportunities there?