| Resources |
 |
History
of fishing in New Zealand |
 |
| Aim |
| To
assess your ability to interpret statistical information. |
| |
| Task |
| 1 |
History
of catch
Look
at the graph of total catch history in New Zealand
waters. |
Total
NZ fish catch
for all species 1890-2000 |
|
| |
a |
State
in one sentence the main trend in this graph. |
|
b |
There
are two pronounced peaks in the graph. Suggest reasons
for the sudden declines in total catch levels after these
peaks. Explain why there has been an increase in the total
New Zealand catch. |
| |
|
| 2 |
Squid
Graph
the following catch data for New Zealand squid:
|
| |
| Year |
Total
Catch
(tonnes) |
1981
|
37,803 |
| 1982 |
86,483 |
| 1983 |
89,426 |
| 1984 |
124,737 |
| 1985 |
89,335 |
| 1986 |
71,765 |
| 1987 |
69,235 |
| 1988 |
69,440 |
| 1989 |
113,506 |
| 1990 |
59,008 |
| 1991 |
38,576 |
| 1992 |
60,589 |
| 1993 |
37,570 |
| 1994 |
73,231 |
| 1995 |
99,299 |
| 1996 |
unknown |
| 1997 |
unknown |
|
|
Suggest
reasons for the pattern you see in squid catches. |
|
| 3 |
Maximum
Sustainable Yield (MSY) Graph |
| |
Click for larger image
|
| |
As
effort increases, catch also increases until a maximum
is reached. Any increase in effort beyond this point still
results in reduced total catch. The point of maximum catch
is the MSY. |
| |
a |
Why
does an increase in effort beyond the MSY still result
in a reduced total catch? |
| |
b |
If
fishers fish above the MSY what could happen to the fish
stock? |
| |
c |
Why
is the MSY a useful tool for fisheries management? |
top
|
| Assessment
B: criteria and marking |
| Assessment
criteria |
|
Level
1: Identifies relationships in information. |
|
Level
2: Identifies relationships in information and partially
explains them. |
|
Level
3: Identifies and explains relationships in information. |
|
Level
4: Identifies and explains relationships in information
and partially elaborates on the explanation. |
|
Level
5: Identifies and explains relationships in information
and elaborates on the explanation. |
|
| Marking
schedule |
|
Level
1: Can state the general trend in the History of Catch
graph and can graph the squid data. |
|
Level
2: Can suggest reasons for the sudden declines in the
catch graph, and suggests a reason for the overall rise. |
|
Level
3: Can suggest a reason for the variable pattern in squid
catches (see notes below). |
|
Level
4: MSY graph - Recognises that if fishers fish beyond
the MSY, overfishing may result. |
|
Level
5: MSY graph - Recognises that: |
| |
|
If
overfishing continues there is a risk that the fisheries
may collapse. |
| |
|
The
MSY is a useful tool for management because the government
can use it to set safe fishing levels for quota. History
of Catch graph: Links trends in graph to the declaration
of the EEZ in 1978, the introduction of the QMS in 1986
and the development of deepwater fisheries. |
|
top
|
| Note
to teachers |
| History
of catch |
|
Catch
levels peaked in the late 1970s because of foreign fishing
activities. They fell away sharply after New Zealand declared
the 200-mile EEZ and cut back on foreign fishing. |
|
Catches
peaked again in the mid 1980s as commercial fishers tried
to build up a sizeable catch history (quota was allocated
on the basis of catch history when the Quota Management
System was introduced in 1986). |
|
The
total New Zealand catch has increased, largely because
of the development of new deepwater fisheries from the
1970s onwards. |
| |
| Squid |
|
The
pattern in squid catches occurs because squid is a one-year
species. It is harvested like a wheat crop, but leaving
sufficient to spawn and produce the next year's harvest. |
|
Spawning
and hatching time the previous year, and subsequent growth
rates, probably depend on water temperature. Also, the
time of arrival and departure of the squid fleet varies,
depending on its fishing activities in other regions in
the northern hemisphere and other competing southern grounds,
such as the prolific Falkland Islands area. These factors
all have an influence on the abundance of squid in the
following season and the size of the catch. |
|
| MSY |
|
Fishing
beyond the MSY results in reduced yields, because too
many mature adults have been removed from the population
to allow stocks to rebuild. |
|
Fishing
beyond the MSY could result in the commercial collapse
of the fishery. |
|
The
MSY is a useful management tool because it is a benchmark
for setting the Total Allowable Catch level. |
