US Conference looks at ocean ranches
The concept of a ranch conjures up images of wide, open Wyoming spaces, cowboys and cattle, but a recent conference in Seattle, United States, discussed the concept of ranching wild fisheries.
Te Ohu Kaimoana senior fisheries analyst Alan Riwaka attended the September conference and found ocean ranches could be applied to the New Zealand fisheries situation.
 |
| Manila clams being processed |
“There is a need to apply land based farming practices to the ocean,” Alan says. “Increasingly, this is beginning to occur in New Zealand within a variety of fisheries, including hoki, orange roughy, and paua. There was a clear message from the conference that many governments are managing fisheries on too large a scale to be effective.”
Ocean ranching involves hatching a species of wild fish in a land or sea based farm and using them to re-seed wild stocks, to be later fished. Alan says that enhancement and ocean ranching in New Zealand were only likely in situations where the stock is of high value in terms of both economic and cultural value, for conservation purposes, or where juveniles can be produced in very large numbers at low cost.
“Enhancement is one of a number of tools for managing fisheries sustainably – particularly where they have been over-fished,” he says, although this is not an end in itself. “There is much more to be gained through effective management of natural stocks and ensuring stocks are not over fished.”
He added that there existed opportunities to create man-made reefs to accommodate sedentary stocks and trials in the United States showed a 20 percent increase in sea production could be achieved through these.
 |
| Seeding Manila clams |
The world demand for fish is outstripping supply and natural fish production from the oceans is decreasing. Currently, enhanced fisheries account for no more than two percent of global fish production.
Alan says the New Zealand Challenger scallop fishery was held up at the conference as one of the successes of stock enhancement, despite problems currently being experienced in that fishery.
He says more work is required on stock-holding capacity. This needs to be scientifically and not politically determined as overstocking can have a detrimental effect on stocks. For sedentary stocks, enhancement should occur mainly in locations where wild stocks have been depleted.
If you have any news or events coming up that you'd like covered
in an issue of Te Tai Pari, drop us an email at
Tiakina ngā rawa hi ika, a tātou kaimoana mo ngā uri whakaheke
Protecting Māori fisheries assets for future generations