Download presentation
Presentation is loading. Please wait.
1
INCOFISH Shifting Perspectives on Baselines Joanne Phillips Maritime Historical Studies Centre University of Hull Blaydes House 6 High Street Hull HU1 1HA Estonian Marine Institute 3 March 2006
2
Aims and Objectives Propose ideas and pose questions for the successful placing of baselines
3
Main Point to Consider The baseline should reflect the need for world wide conservation efforts; we need both LME- and world- specific baselines
4
Structure of the Paper Demonstrate: 1.Different usages of the term Shifting Baselines 2. The importance of Shifting Baselines to the marine biologist 3. Issues with Setting Baselines 4. Discuss the value of the baseline
5
1. The Usage of the Term Shifting Baselines
6
The Definition A baseline is defined by the point against which all other points can be compared. A baseline is considered to have shifted where the point of reference at one time is different from at a later time because of a known or assumed progression of conditions.
7
Shifting Baselines for Marine Biologists Long history of human intervention; short history of investigation People adjust to continuous degradation With time, there are reduced expectations Need to develop historical framework Objectives for restoration Changing expectations requires direct local experience and education
8
Nassau Grouper (Epinephelus striatus) The Caribbean used to have large schools Landings are declining in Cuba & the U.S Most anglers now accept they are inconspicuous Its exploitation in many areas is now permanentlyprohibited
9
Decline In Marine Species
10
Shifting Baselines for Biologists Occupied bald eagle nests in Maryland have increased steadily from 51 in 1979 to 383 in 2004 Worldwide, the bald eagle is in danger of extinction Bald Eagle
11
Shifting Baselines for Scientists Increased levels of smog seen over cities on warm summer days Residents of Tehran were told not to go to work or school for two days
12
Shifting Baselines for Economists The baseline for stocks are set for each person at when they first bought a share
13
Shifting Baselines for Politicians Politicians make more and more radical claims When most extreme claim is dropped, others seem ‘normal’ in comparison A new and self-interested definition of what is normal is defined
14
Shifting Baselines for the Public Public lowers their standards to the point that they accept things that once would have been unacceptable Expectations for themselves are changing Expectations of nature are diminishing
15
There are millions of examples. The shifting baseline syndrome is present in most areas of human life The syndrome is a result of human nature
16
2. Comparison With the Marine Biologist
17
Similarities The crucial similarity for all uses of a shifting baseline is that the point of reference has changed This restricts the information known on the subject Acknowledging the baseline has shifted means that the wider picture can be seen
18
3. Issues With Setting Baselines
19
Objective of Setting the Baseline A pristine environment could never be found; man has always impacted on the aquatic resources If we are not aiming towards pristine, what are our aims? Is it irresponsible to set a baseline where the stocks are known to be depleted?
20
Where Should a Baseline Be Set? According to changes in fishing (for example the start of commercial fishing, or the start or trawling)? According to species fluctuations? Could baselines be set every 10 years regardless of fluctuations to avoid bias? Could it be based on the CPUE; that way boat size and power have been taken into account as well as fish caught
21
Data Fluctuations and Anomalies Seasonal fluctuations Natural cyclic fish stock fluctuations Pollution can attract and repel different species Land use change Global warming may shift species range Fluctuations of predators, prey and competitors A regression line can smooth out anomalies
22
Time Series Harper (1971) has identified three main influences of a time series: –The actual trend; the natural fluctuations of the data due to their greatest influence –Seasonal variation –Random variation; factors that have no pattern
23
Understanding the Trends These influences need to be separated in order to fully understand the series For example, fishing effort in Newfoundland, 1698 - 1827
24
Wars Catch CPUE
25
Other (Unknown) Factors Condition of the stock Pollution Land use change Natural species fluctuations Change in species targeted Power of fishing vessel Fish-finding technology advancements
26
To What Extent Can Historical Data Be Used? Fishing pressure is highly dependant on localised conditions that are often unknown Were certain grounds/species protected or heavily exploited because of religion or tradition? As much information as possible should be compiled to explain trends
27
Data Integration If we cannot quantify qualitative historical data, what can we do with them? Can we give each influence a numerical value? Would this introduce bias into the results? This will move us away from typical scientific data
28
How Representative Is the Numerical Data? Any one measurement (i.e. CPUE) takes very little into account Statistics can only supply trends; qualitative historical information must be used to explain these It is not feasible to extrapolate our data back in time further than we have the data for Does our data go back far enough for us to construct valuable baselines?
29
Spatial Developments Not only the amount of fish fished is increasing, but also the area fished is increasing. Fish numbers will appear to increase for a while after the area first expands. Could an area extension be a baseline?
30
Newfoundland Expansion of Fishing Grounds
31
Area Fished 1698 - 1776 1698 1776 3 times as many fish 5 times bigger!
32
Same Species, Same Fish? Fishing pressure changes genetic composition of species especially of size at maturity As pressure increases, the strains that are less resilient to fishing will disappear. Man has therefore shaped the genetics of the population To what extent can fish of 500 years ago be compared to those of the same species today?
33
What Is the Use of the Baseline? It has been known for at least thousands of years that stocks are being depleted Our work should not be simply more evidence of this; it should take this evidence a step forward
34
4. The Value of the Baseline The Way Forward
35
The Importance of the Baseline What can a baseline set in the 1970s really tell us? We need to define ‘the baseline’ Why find the baseline?
36
The Way Forward Could we map out how the world-wide aquatic environment should look? Large-scale restoration or significant drop in fishing effort is infeasible World-wide comparison of different resources and how these link together The baseline should reflect the need for world-wide conservation efforts; we need both LME- and world- specific baselines
37
Thank You J.Phillips@hull.ac.uk
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.