Inland Fisheries and Riparian Ecosystems 1 Ogutu-Ohwayo R., K.N. - - PowerPoint PPT Presentation

Impacts and Adaptations to Climate Variability and Change in Inland Fisheries and Riparian Ecosystems

1Ogutu-Ohwayo R., K.N. Odongkara1, W. Okello1, S.B. Wandera1, J. Efitre2, M. Bwambale1, V.

Natugonza1

1 National Fisheries Resources Research Institute, Jinja, Uganda 2 Departments of Biological Sciences, College of Natural Sciences, Makerere University,

Kampala, Uganda

Outline of the Presentation

I. General Aspects of Climate Change; II. Vulnerability and Impacts of Inland Aquatic Systems and Fisheries;

• III. Adaptation and Coping Strategies by Fishers and Riparian

Communities;

• IV. Conclusions and Recommendations for Action; and

V. Mainstreaming Climate Change in Fisheries.

• I. General Aspects of Climate Change

• 1. Definition and Parameters of Climate Change

Climate is the average weather of a given region averaged over a long period (at least 30 years) & includes weather parameters such as:  Temperature;  Droughts and dryness;  Atmospheric pressure;  Humidity;  Wind speed;  Precipitation (rainfall);  Sunshine; and  Cloud cover Climate variability and change involves a shift in these parameters due to natural or human factors

• 2. Manifestations of Climate Change

Climate change is manifested in the form of:  Rising temperatures;  Increased evaporation;  Fluctuation in precipitation (rainfall);  Floods and wetness;  Droughts, desiccation and dryness;  Intense winds, storms and hurricanes; and  Re-configuration of ecosystems & organisms including changes in their productivity and biological characteristics.

• 3. Socio-economic Impacts

Displacement of communities;  Damage to infrastructure;  Water and food shortages;  Poor sanitation;  Increasing incidences of diseases e.g. cholera, & bilharzias; and  Changes in resource availability.

 Climate change is caused by global warming due to accumulation of green house gases (GHG) mainly CO2 in the atmosphere from burning of fossil fuels.

 It is exacerbated by deforestation

which reduces the capacity to absorb GHGs.

 The GHGs have accumulated for

• ver 100 years & even if emissions

were eliminated it would not immediately stop global warming. Hence the need for development of adaptation strategies.

• 4. Causes of Climate Change

• 5. Vulnerability

 The poor are most vulnerable to climate variability and change and there is need to safeguard them.  About 30% of Ugandans live below the poverty line and 70% depend

• n crops, livestock and fisheries which are sensitive to climate

variability and change. A large proportion of Ugandans are therefore vulnerable and there is need to understand the impacts of climate change on these sectors and to equip, especially the poor, with knowledge and practices to adapt and become more resilient.

 The East African Great lakes region is rich

in inland aquatic resources

Uganda has 5 large lakes, 160+ small lakes,

rivers & wetlands covering about 21% of the national surface area.

 These aquatic systems, most of which are

shared with her neighbors, cover about 80,000 km2, hold 3,000 km3 of freshwater, & produce about 1.5 million tons of fish annually

 They are important sources of: Food,

income & export earnings; Biodiversity; Water for domestic, agriculture & industrial use; Hydropower; Navigation & Modulation of local climate.

• 6. Importance of Aquatic Resources

• 7. Addressing Impact of Climate Change

 Addressing climate change in Uganda and elsewhere has concentrated

• n crops, livestock & forestry & less on fisheries despite the high

economic importance of fisheries to the national economies and vulnerability of fish production systems to climate variability and change.  There is no adaptation plan of action for fisheries in the Ugandan National Adaptation Plan of Action (NAPA) to climate change.  NARO and NaFIRRI recognize climate change as a major problem but fisheries research has not previously had it among its core research areas. Local, regional and international examples show that climate change affects riparian & aquatic ecosystems fisheries, & livelihoods, & should be mainstreamed into fisheries & NAPA.

• 8. How Climate Change Operates

Increased temperatures affect physical, chemical & biological processes Greenhouse gases trap heat The heat increases the Earth’s temperature Result in socio-economic consequences

• 9a. Evidence of Climate Change

 The Intergovernmental Panel on Climate Change (IPCC) has reported that the last two decades of the 20th century were the warmest;  The average global temperature increased by 0.7oC since mid-20th century & that over Africa by about 0.5oC;  The surface temperature of aquatic systems increased; and  Fluctuations in intensity of storms, floods, droughts, hurricanes, precipitation & frequency of droughts has increased.

The frequency of drought in Uganda increased since 1970s (NAPA, 2007) which coincides with the period of the highest global warming reported by IPCC showing that Uganda is being impacted by climate change.

• 9b. Frequency of Droughts in Uganda

• II. Vulnerability and Impacts of Inland Aquatic

Systems and Fisheries

• 10a. Vulnerability of Fish Production Systems

 Fish production systems are

highly vulnerable to climate variability and change.  Lakes in Eastern Africa have experienced fluctuation in water levels, desiccated and even dried due to climate variability and

• change. (Nichoson & Xungang, 2001)

• 10b. Lake Chad Shrunk to 10% its size within 15 years between 1972 (left)

and 1987 (right) [Dropped 22,903 to 304 km2:1963 & 2001]

• 10c. Changes in water levels of Ugandan Lakes

Edward and George had low water levels over the past 5000 years, Albert was reduced, Victoria was dessicated as recently as 12,000 years BP and the water levels of these lakes have fluctuated in recent times as demonstrated by lakes Victoria 1870 - 2000 (top) and Kyoga1948

• 2003,

(bottom) water levels. Although these changes are due to natural cycles, they show that aquatic systems are vulnerable to human induced changes in climate.

• 10d. Trends in Annual Precipitation near Lake Wamala 1950-2004

Annual precipitation around Lake Wamala varied due to natural causes but has become more erratic since the about 1975 when climate change became more intense

• 10d. Fluctuations in Area of Lake Wamala

The lake covered ~250 km2 in 1980s, shrank to about half in early 1990s, recovered from late 1990s into late 2008 but the water gauges were still above water level by 2011 suggesting that it had not fully recovered

July 1984 March 1995

• Dec. 1999
• Feb. 2008

May 2011

• 11. Components of Aquatic Ecosystems Impacted

 Riparian ecosystems & infrastructure;  Aquatic habitats;  Aquatic productivity processes (nutrients, phytoplankton & Invertebrates);  Life history of fishes;  Fisheries production; and  Livelihoods of fishery dependent communities

• 12a. Effects on Riparian Ecosystems and Infrastructure

 Flooding;  Desiccation and shrinkage;  Infrastructure damage;  Displacement of communities;  Effect on ecosystem integrity and biodiversity including wetlands.

• 12b. Impact of Floods on Lake Kyoga

El-Nińo rains of 1997/98 dislodged water hyacinth & papyrus Cyperus papyrus which blocked the outlet, raised the water level by 1.5 m, increased the volume of the lake from an average

• f 7.7 km3 in 1997 to 13.6 km3 in 2003, flooded 580 km2 of land,

displaced human populations, destroyed infrastructure and caused economic losses

• 13. Effects on Aquatic Habitats

 Fluctuations in water levels in both shallow and deep lakes;  Shrinkage and even desiccation and as in Chad, Chilwa and Wamala; and  Affects water circulation, causes stratification and enhances anoxia (oxygen deficiency) in deep lakes

• 14a. Effects on Aquatic Productivity Processes

 Changes in nutrient circulation;  Changes in phytoplankton primary production & composition;  Changes in invertebrate production & composition;  Alteration in food-webs; and  Shifts in fish communities and fisheries.

Warming of surface waters of Lake Tanganyika by about 2oC is estimated to have decreased algal productivity by 20% and fisheries yield by 30% (O’Reilly et al., 2003)

• 14b. Changes in Phytoplankton Production in Lake Tanganyika

• 15a. Impacts on Life History of Fishes

 Physiology of fishes which are cold blooded;

 Composition and diversity;  Distribution;  Relative abundance;  Population structure;  Recruitment rates;  Biological characteristics of fishes (food and feeding habits, size at maturity, sex ratios, condition factor etc.).

• 15b. Changes in Water Level, Life-history Parameters and

Fishing Practices for Nile Tilapia on Lake Wamala

Parameter Water depth (m) 1.5 4.0

• Max. Size (cm)

20 40 Size at maturity (cm) 15 25 Mesh size of net used to fish (mm) 51 102 Fluctuations in depth of Lake Wamala between 1.5 and 4 m was accompanied by fluctuations in max. size of Nile tilapia between 20 and 40 cm, the size at first maturity between 15 and 25 cm, and shifts in the gillnet mesh size used for fishing between 51 and 102 mm.

In the North Atlantic, anomalies in Northern Hemisphere temperature and changes in sea surface temperature were accompanied by changes in composition of calanoid zooplankton prey and recruitment

• f their fish predators (haddock & cod)

(Barange and Perry, 2009)

15.c. Changes in Environmental Factors, Zooplankton Prey and Recruitment of Fish Predators

• 16a. Impacts on Fisheries Yield

 Relative abundance, composition and size structure of exploited stocks and fish catches;  Types and sizes of gears used to exploit the fisheries as in Lake Wamala; and  Fishery yield.

On Lake Chilwa fluctuations in water level was strongly correlated to fishery yield. (Allison et al., 2007)

• 16b. Fluctuations of Water Level & Fishery Yield on Lake Chilwa

• 17a. Interactions of Non-climate Stresses

Climate factors may not operate independently but can interact with non- climate factors including: Over-exploitation; Non-native species introductions; Flow obstruction by construction of dams for hydro-power and irrigation; Change in land use practices; Pollutants and contaminants; Eutrophication & nutrients enrichment; Human population growth; and Poor natural resources management. Exploitation has been the main stressor of fisheries but other factors have become increasingly important overtime but there has been less attention to impacts of climate variability and change.

In Uganda, over-exploitation was the most important stressor since the beginning of the 20th century and was responsible for the initial decline in fish stocks. Increases in water levels contributed to changes in some fishes after the El Nino rains of 1961. Non-native species increased fishery yield and contributed to losses in biodiversity in lakes Kyoga and Victoria and interacted with eutrophication since mid-1960s.

• 17b. Operation of the Stressors in the Ugandan Fishery

Climate change became important around 1970s and may have contributed to shifts in fish communities to pelagic species such Mukene, Muziri & Nile perch which dominate the fisheries of lakes Victoria, Kyoga and Albert but its role has never been examined.

• III. Adaptations and Coping Strategies by

Fishers

• 18. Adaptation and Coping Strategies of Fishers

 Diversifying or intensifying fishing operations;

 Changes in fishing methods, types and sizes of gears used;  Migrating to less affected fisheries;  Diversifying to crops, livestock forestry & other income generating activities; and  Resorting to social capital and community support. There is however need to develop appropriate adaptation strategies applicable to specific local situations.

• IV. Conclusions and Recommendations for

Action

• 19a. Conclusion & Recommendations for Action

Climate change presents threats & opportunities especially for the poor & vulnerable. There is need to improve knowledge of its impacts for specific aquatic systems and resources including interactions with non- climate factors by:  Establishing a network of scientists, policy makers, managers and the general public to address climate issues in inland fisheries; Providing knowledge on the relationship between climate parameters & physico-chemical conditions, aquatic productivity processes, fisheries production and yield; and Identifying, prioritizing, and testing local adaptation strategies.

• 19b. Improving Policies, Legislation and Governance

Climate variability and change causes fluctuations in resource availability that necessitates flexibility in policy, legislation and governance systems. There is need to review, adjust and improve policies, regulations and governance systems to accommodate fluctuations in resources by: Reviewing existing policies, regulations and governance systems; and  Preparing policy briefs to guide adjustments in policies, regulations and governance systems to accommodate changes in resource availability.

• 19c. Building Capacity

Climate variability and change has not been part of most research and educational programs. The capacity to address it in most sectors is

• weak. There is need to build capacity in research, academic, policy and

public institutions to generate and share information by:  Developing training curriculum; and  Promoting specific training in climate change.

• 19d. Increase Awareness

Climate change is little understood by many stakeholders. There is need to increase awareness among scientists, policy makers and the general public by:  Developing an information and communication strategy and action plan; Preparing awareness materials; and  Conducting awareness rising events.

• 19e. Mitigation of Climate Change

Climate change is caused by GHGs emitted mainly by developed countries and reduction of the capacity to absorb GHGs by deforestation. There is need to:: Intensify and lobby for development and implementation of protocols aimed reducing in emission of green house gases such as the Kyoto Protocol; and Contribute to reduction in GHG through aforestation, protecting wetlands and riparian ecosystems.

• V. Mainstreaming Climate Change in Fisheries

and NAPA

• 20. Mainstreaming Climate Change in Fisheries and NAPA

NaFIRRI with support from The Rockefeller Foundation has initiated a process of mainstreaming climate change in fisheries research and NAPA using case studies of two small shallow lakes (Wamala & Kawi) which have manifested impact of climate variability and change but whose surrounding communities seem to have different capacities to adapt & plans to extend the work to deeper lakes such as Victoria & Albert.  The plan involves creating a network of scientists, policy makers and the general public to address climate issues; generating knowledge on the relationship between climate parameters & physico-chemical conditions, productivity, fisheries production & fisheries of the target aquatic systems; Development and piloting adaptation strategies; Improving policies, regulations and governance systems; Building capacity; & Increasing awareness.

• 21. Expected Outputs and Outcomes

The expected outcome of the plan is to increase resilience and reduce vulnerability to poverty & food insecurity and increase resilience of small scale fishers and riparian communities. The specific outputs are to have:  Capacity for generating knowledge address climate change issues improved;  Climate change introduced in fisheries research and mainstreamed in Ugandan NAPA;  Knowledge to guide forecasting of changes in riparian ecosystems, aquatic productivity, fisheries production, and adaptation strategies generated and piloted;  Policies, legislation and governance systems to address climate issues improved; and  Awareness in climate change issues in inland fisheries increased.

• 22. Acknowledgements

This brief was first presented at a forum of the Uganda Journalists Association in December 2011. We are grateful to the association for inviting us to share the information. We are specifically grateful to The Rockefeller Foundation for supporting our studies of climate change in inland fisheries.