Evaluation of Fish Cages in the Gulf of Eilat

Evaluation of Fish Cages in the Gulf of Eilat

Report for the Ministries of Infrastructure, Environment and Agriculture

Prepared by the International Expert Team

September 20, 2004

Professor Marlin J. Atkinson

Hawaii Institute of Marine Biology

University of Hawaii

PO Box 1346

Kanoehe, Hawaii, USA 96744

Professor Yehudith Birk

The Israel Academy of Sciences and Humanities

Albert Einstein Square

P.O.B 4040, Jerusalem 91040

Fax & phone: +972-8-9473654

Professor Harald Rosenthal

Institute for Marine Science

University of Kiel

Duesternbrooker Weg 20

24105 Kiel, Germany

Table of contents

IET Statement to the Government ………………………….……………………...3-4

Executive Summary ………………………………………………………………...5-6

Introduction ……………………………..…………………………………………….7

Recommendations ……………………………………………………………….…8-13

Findings …………………………………………………………………………...14-21

Appendix A: Is the Reef Deteriorating? ……………………………………………...22

References …………………………………………………………………..…….22-23

International Expert Team (IET) on the Gulf of Eilat:

Statement of Findings and Recommendations to the Government of Israel

The IET wishes to congratulate the government of Israel on providing the means to make recommendations based upon an objective process, which included quality data, scientific discussions and consensus building. We were appointed by the Director Generals of three Ministries: Agriculture, Environment, and Infrastructure. Oversight of the program was by the three chief scientists of those ministries. Numerous interdisciplinary projects were conducted and provided a better, but not complete, understanding of the complexities of the Gulf. We all are aware that the reef in Eilat is an irreplaceable natural treasure.

Findings:

The findings briefly listed below are based on:

1) monitoring and research conducted as part of the IET program,

2) reports and scientific publications provided by Israel scientists, and

3) discussions with Israel scientists.

Finding No 1: Water currents in the Gulf are faster and more variable than previously assumed. This is very important. The northern Israel end of the Gulf has an open exchange with the rest of the Gulf. Thus nutrients and plankton from the fish farms move into the whole Gulf relatively rapidly.

Finding No 2: Nutrients from the fish cages mix into deep water, widely over the whole Gulf, not just near Eilat.

Finding No 3: Nutrients in the deep water of Eilat have been increasing with time, as part of a natural cycle. Nutrients from the fish cages are only a few percent of this amount.

Finding No 4: Nutrient delivery to the surface water from Eilat deep water varies from season to season, year to year. This is a natural phenomenon.

Finding No 5: Excess organic material from the fish farms is confined to a relatively small area near the fish cages; it does not influence the Eilat reef.

Finding No 6: Fish farmers have by now reduced nutrient inputs to the Gulf up to 15% through better management practices.

Finding No 7: Coral and associated reef organisms grow and proliferate near the cages. There is some disagreement as to whether they can reproduce and flourish there.

Finding No 8: Diseases in natural populations of Eilat fish and caged fish are minimal but can become potentially a severe risk.

Finding No 9: A number of contaminants known to affect marine organisms were reported.

Recommendations:

Recommendation No 1: Do NOT increase nutrients from fish farms into the Entire Gulf.

Nutrients in the water flowing through the Straits of Tiran is the largest source of nutrients to the gulf; fish farm nutrients are presently 2-5% of this source.

Recommendation No 2: To understand nutrient changes in the Gulf of Eilat, the Eilat deep water must be continually monitored for specific environmental parameters, regardless of the presence of fish cages. The monitoring program should be a national program affiliated with the international ocean observing systems.

Recommendation No 3: Move fish farming to land-based system within clearly defined time period. During the transitional period, specific updated mitigation strategies must be employed. Sufficient and timely funding is critical.

Recommendation No 4: Expedite development of artificial coral reefs as a mitigation of the local impacts of the fish cages, a nursery for marketable corals and an educational and research tool..

Recommendation No 5: Develop a certified scuba diving program on these artificial reefs. Severely limit tourist scuba diving in the nature preserve.

Recommendation No 6: Identify a government authority for the implementation and enforcement of environmental and resource use guidelines.

Recommendation No 7: Consider other critical threats to the reef, other than fish cages.

Justification:

Even though present nutrient inputs, spread over the entire gulf, are relatively small but significant, any further increases, or uncontrolled additions may alter the functioning of this system in the long term. Combined with unknown and long term risks associated with unpredictable biological interactions, we have made the above recommendations.

General Comments:

We suggest that the government considers whether the reef system at Eilat is an untouched natural ecosystem, without any human interference, or whether it is a natural resource with multiple users and affected or controlled by a range of human activities.

Recognize that the entire reef may be lost to “bleaching,” a response to warming of the surface water. This may happen suddenly and regionally from global climate change. Artificial reefs in open water can act as a reserve for corals.

Recognize that the deep water has been increasing in nutrients as part of a natural cycle, and if there is a deep mixing soon, it will create a large algal bloom.

Thank you for the opportunity to report our findings.

Executive Summary

We all are aware that the reef in Eilat is an irreplaceable natural treasure that must be saved and nurtured for future generations.

The IET was originally formed in response to the idea that nutrients from the fish farms may be accumulating in the sediments and deep water of Eilat, creating a pending ecological disaster, the “time bomb” hypothesis. The IET was tasked to identify sources of pollution and develop an estimate of carrying capacity (IET Report 12-04). This IET report addresses some of the findings from research and monitoring, and makes specific recommendations on the fate of the fish farms. The following paragraphs are a brief review of IET results and the overall of recommendations, followed by our specific recommendations and findings.

Overview of the Findings

Nutrients from the fish farm mix to background concentrations and are removed by phytoplankton within several kilometers of the fish cages, depending on current conditions. These organic materials are exported over days to weeks into the central portion of the gulf; they do not accumulate in the sediments in the vicinity of Eilat. They enter the food chain and ultimately are distributed into the deep water and sediments of the entire Gulf, representing several percent of the water column nutrients. Fish farm nutrients are also somewhere between 1-5% of the largest nutrient input to the Gulf, exchange of water and nutrients in the Straits of Tiran. This mechanism is very different from the original “time bomb” hypothesis (the building of a nutrient reservoir in the sediments of Eilat.) Eilat water changes nutrient inventory seasonally and inter-annually based on the distribution of the deep water. There are some details not yet understood and to further confirm this mechanism, a monitoring of station A and sampling of station B are firmly recommended. The monitoring will also provide a basis to monitor the inputs for the overall Gulf, over decades. In this way the carrying capacity of the Gulf can be actually managed.

The fish farms affect the water locally as described above, and documented in a number of earlier IOLR reports. The water near the fish farms is elevated in nutrients relative to water near the reef, but the nutrient concentrations near the fish farms (50-100m) are within ranges of natural nutrient concentrations reported for other coral reefs, and are well within concentrations that allow coral to grow. Consequently corals and associated organisms grow and flourish immediately adjacent to the fish cages. There is one report, however, that corals, have impaired reproduction near the fish cages, but this work is incomplete because it was observed only in few individuals and was not designed to assess recruitment success at the population level.

Interestingly, three years ago the IET reported that the Eilat reef was deteriorating. During this review, however, there was more evidence presented of reef improvement than of reef decline. Thus there are conflicting reports and a clear analysis of existing data and monitoring goals for the reef needs to be established.

Overview of the Recommendations

The IET does NOT recommend immediate removal of the fish cages, instead the IET recommends hastening research toward a land-based re-circulating system, gradually increasing the rearing of juveniles and larger fish on shore and only growing out the largest fish in the Gulf. The IET believes with immediate initiation, adequate funding and an eight year time-table the fish farming can gradually and almost entirely transfer to land. Land-based expansion of aquaculture to re-circulating systems is now a worldwide effort. The IET recommendation is based on a risk management precautionary approach, because ecological factors may be operating synergistically or “chaotically,” including unknown inputs from anthropogenic activities along the other coasts of the Gulf, natural fluctuations in the inputs of deep water nutrients, changing weather patterns, heating of the waters, competition from exotics, and disease, interacting with compromised organisms from the effects of contaminants. The fish farms are the largest anthropogenic nutrient source. With these considerations, the IET recommends extensive reduction of the fish cages. The known impacts of the fish cages, now, however are relatively minimal compared to the impacts postulated based on the time-bomb hypothesis. The immediate environmental priority should be to mitigate the local and near-field impacts of the fish cages.

Contaminants and other impacts are reported at several sites near Eilat, including heavy metals, TBT, detergents, sediment re-suspension, and Diver activity. These are more directly related to tourism, than to fish farming. Therefore, immediate removal of the fish cages without proper attention to mitigation measures for the above cited tourism-related activities will not guarantee healthy reefs. Further, the expansion of tourism industry (including the necessary infrastucture development) has to be considered as equally critical. Thus the IET recommends a precautionary approach, representing a mixture of sound environmental stewardship and advances in the technology of mariculture. This project should be adapted as a whole. We further recommend a joint team approach by the scientists of IOLR and IUI. They should focus on two important questions; continued verification of developing a monitoring tool by assessing the deep water at Station A and secondly, answering the basic question on assessing the effects of the fish cages on organism growth and reproduction. The IET commends the scientific effort and scientific leadership of the lead scientists of IOLR and IUI.

Introduction

In principle, four management options regarding the future of the fish farms can be envisioned. They are listed below with their considerations:

1. Close fish farms immediately: There are no reasons that the fringing reef will improve or be saved. Large-scale processes affect the system, and clear impacts are not established. This approach is just not realistic nor responsible.

2. Keep fish farms operating, business as usual: Lack of precautionary measures, lack of environmental stewardship, and lack of commercial potential for future development of the industry. There is a responsibility to guide development towards long-term livelihood of the community.

3. Continue farms with mitigation measures: Employ a series of mitigation measures, develop codes of conduct (Best Environmental Practice & Best Available Technology), continue monitoring, attempt sustainability at the status quo. To continue the farms as a permanent activity in the Gulf does not offer any hope for expansion. Therefore, this activity can only be seen as an option for the medium term. Strict mitigation measures will be required for which the costs will be high towards the end of this period, and no incentive is left for the farms to comply with these measures. Unacceptable impacts towards the final years of the life time of the operation may occur.

4. Continue farms with step-wise transfer to land-based systems: Invest strongly, with- out delay, in alternative rearing technology onshore. Once ready for application, decide on total removal of cages or small-scale continuation. These three choices are potential ways for future development and economic growth, while at the same time employing a precautionary approach to protect the environment. Most of the recommendations focus on this option, accompanied by reasonable mitigation measures imposed on fish farms. These mitigation measures offer in themselves development potential for environmentally friendly and commercially viable activities, serving also other stakeholders in the coastal zone (e.g. tourism).

In consideration of these four management options and the various findings, the following recommendations were formulated.

Recommendations

Recommendation No 1: Do NOT increase nutrients from fish farms into the ENTIRE Gulf. Nutrients in the water flowing through the Straits of Tiran is the largest source of nutrients to the Gulf; fish farm nutrients are presently 1-5% of this source.

Nutrients are not accumulating in the sediments near Eilat and are spreading over a much larger area of the gulf, thus the entire Gulf can be treated as the sink for these nutrients. While 1-5% (see finding below for explanation) seem like a small amount of nutrients, they are significant. In view of not knowing the extent of inputs along the remaining Gulf coast from other countries, and the variability in the Gulf deep water, the IET recommends not increasing the nutrient load to the entire gulf. The fish farms also affect the environment within several kilometers of the cages; and it is yet to be established how beneficial or detrimental this impact is to the natural environment. Expanding the industry will certainly affect the local environments. Thus the IET does not recommend immediate and complete removal; a gradual reduction in size is recommended.

Station A deep water must be monitored for nutrients (nitrate, nitrite, phosphate, ammonia, dissolved organic nitrogen) oxygen, temperature, salinity, and perhaps CO2 chemistry such that the carbonate ion can be calculated for both surface and deep water, and even other compounds of interest. See further discussion below in findings.