Issue 16 ~ July 2019

The monthly newsletter of the Lower Breede River Conservancy Trust

How your membership

can help the Breede

All estuaries in South Africa are under severe pressure resulting from over-exploitation of natural resources, habitat destruction and deterioration of water quality.

If you take an active interest in, or use, the Breede River Estuary we hope that we can persuade you to become a member of the LBRCT and to support our endeavours on your behalf by way of your contribution to these efforts.

The authorities who are ultimately responsible for ensuring protection of our valuable natural resources are contributing, however, they simply cannot afford to allocate sufficient of their available funds to meet the estuary’s conservation needs.

Your membership contribution supplements the funds obtained from the licence fees paid by users of boats; the municipalities by way of supplementary grants constrained by their many other social upliftment and development imperatives, and grants from those government agencies to whom we are contracted.

There are 62 estuaries in the Western Cape and all need support. The Breede is one of the two largest and most important and we all need to play a role in preserving it. 100% of your membership subscriptions are put to the best possible use to help maintain the conservation infrastructure that has taken many years to put in place and initiate new projects such as:

• Turtle and penguin rescue transport

• Environmental education programmes

• Holiday activity programmes

• Funding conservation interns

• Printing brochures, pamphlets, posters and information packs

• Producing and erecting signage

• Materials and equipment for monitoring projects

For R 100 a year, you can assist us with all of the above and add your voice that is so important to ensure that your opinions and concerns are heard. The LBRCT can speak more authoritatively when dealing with the vast number of threats, regulations and legislation that already affect the estuary with the backing of a sizeable member base.

Please think about the future of the estuary and the importance of maintaining its good health for you and your children’s benefit through supporting our effort.

The importance of eelgrass

Zostera species or eelgrass, occurs as dense beds on intertidal and shallow subtidal mud and sand flats in sheltered shallow inlets, bays, estuaries and saline lagoons. The species found in South Africa is Zostera capensis, which occurs mostly along the east and southern coast of our country, with isolated patches near Cape town.

Worldwide rapid seagrass decline has been associated largely with human intervention on coastal processes in the form of industrialization, recreation, watershed runoff, agricultural land uses, dredge and fill operations, eutrophication, and unsustainable fishing practices. This has led to the creation of the World Seagrass Association which holds the World Seagrass Conference, a global network of scientists and coastal managers committed to research, protection and management of the world’s seagrasses.

Steady global loss of seagrass habitats results in loss of important ecological functions and values to human populations, including reduction in fisheries productivity, water quality, sediment stability, and coastal ecosystem biodiversity, environmentally sensitive seagrass areas, should be given priority in technical cooperation and financial aid for sustainable coastal development.

Seagrass meadows are of fundamental importance to the human planet. They exist on the coastal fringes of almost every continent on earth where they and their associated biodiversity supports fisheries productivity. These powerhouses of the sea create life in otherwise anoxic muddy environments where they stabilise sediments, filter vast quantities of nutrients and provide one of the most efficient oceanic stores of carbon on earth. The loss of seagrass from common human induced impacts such as poor water quality, coastal development and destructive fishing leads in turn to the loss of most of the fish and invertebrate populations that they support. To help stabilise our climate and to help ensure we have long-term food security we need to protect seagrasses and promote their renewal and recovery.

Seagrass meadows are important fish nurseries and key fishing grounds around the world. The loss of seagrass puts the livelihoods of hundreds of millions of people at risk and exposes many people to increasing levels of poverty. Seagrass loss should not be an option.

Eelgrass in estuaries has three main threats; local disturbance such as excessive bait collecting or harvesting, Z. capensis has been used in the past for pillow stuffing or in seafood stir-fries. Bad catchment management, erosion in the faster flowing waters upstream causes increase deposition on the eelgrass beds. Infrastructure maintenance in the estuary such as dredging can completely destroy the root system or increase deposition on the eelgrass beds.

Eelgrass have horizontal rhizomes with grass like leaves. The male and female flowers occur on the same leaf. The rangers have not yet seen any flowers on eelgrass in the Breede estuary, this could be that the main form of reproduction is asexual, by the growth and elongation of the rhizome. Flowering occurs during May to June so if you happen to come across a flower please take a picture and post it on our Facebook page with the location.

The rhizomes make an extensive network of branched, creeping underground roots that help bind the sand or mud, which is very important for the control of deposition and erosion within the estuary. If beds are locally destroyed, their protective capacity can only be replaced by financially costly artificial shoreline reinforcements. Beds of eelgrass provide ecological niches for many different organisms. Eelgrass act as nutrient traps and are primary producers forming biodiversity hotspots.

An example of a ecological niche are pipefishes (more about them in the members' newsletter) inhabiting sheltered areas in coral reefs, seagrass beds and sandy lagoons. Some inhabit brackish or freshwater habitats. They feed on small crustaceans using a sit-and-wait strategy, hidden in eelgrass, and with their tube like mouth they create a vacuum that draws their prey into the mouth.

Each of us can play a role in looking after this important habitat so please use and enjoy these areas in the Breede with respect, which will make a big difference in keeping the Breede estuary one of the best places to fish, ski, kitesurf and relax.

July water quality

Changes in salinity were observed between May and July due the arrival of the winter rainfall season. The increase in freshwater input into the system was a result of high rainfall experienced in the area as well as the Breede River catchment. In May and June sites near the mouth recorded high salinities due the marine influence. The arrival of good winter rainfall in July saw a significant decrease in salinity, even at those sites close to the mouth. Freshwater conditions were recorded 17 km from the mouth in July.

The increase in freshwater into the Breede decreased the secchi depth (water transparency). Freshwater input from runoff carries a high suspensiod level which resulted in an increase in turbidity and therefore a lower water transparency.

The arrival of winter saw the temperature drop from 20-23 ºC in May to 14-15.5 ºC.

July bird count

We were lucky enough to find 33 species between the mouth and the Malgas pont. Overall 459 birds were recorded with the usual suspects being the most abundant: Egyptian Geese (109 birds), Yellow-billed Ducks (81 birds), Sacred Ibis (38 birds) and Kelp Gulls (30 birds). Other interesting birds that were recorded were African Fish Eagle, Black-Crowned Night Heron, Black-winged Stilts, Cape Shoveler, Little Grebe and juvenile Common Greenshanks.

Yet again some special birds were found on the trip. A single Terek Sandpiper was found between Powerlines and White House. Some of these summer migrants overwinter in southern Africa and hopefully these birds hang around the Breede mudflats throughout the year. A single Crowned Cormorant juvenile was seen at Kraaltjie. These endemic cormorants are uncommon to rare over their distribution range (Namibia to Tsitsikamma) with about 1900 breeding pairs in South Africa. They are listed as near-threatened on the IUCN red-data list.

June marine debris

Plastic dominated the beach clean-up on Main Beach (84%) and Blokke to the tidal pool (47.2%) with microplastics (plastic smaller than 2.5cm in size) being important at 58% and 15.3% respectively. Other litter types found on Main Beach include large plastic pieces (10%) and nurdles (9%) whereas large plastic pieces (15.3%) and bottle caps (8.3%) were found at the Blokke zone. Foam was the second most important component of the litter of Main Beach (6.1%) while Fishing-related litter (23.6%), particularly fishing line (19.4%) was important at Blokke. Oysterbeds towards Groenpunt was dominated by glass-related litter (38.8%), particularly small glass pieces (20.9%). Plastic-litter (24.8%) and food wrappers (14%) were found in the area.

The marine debris surveys show that while many of our beaches look clean; litter, particularly plastic is a major problem. In order to try and make a small difference to our litter problem the LBRCT and Anchorage Restaurant in Witsand joined forces to offer people a free coffee if they collect rubbish in a bucket on Main Beach. Buckets available at Anchorage Restaurant.

Thank you for reading

We hope you enjoyed this months' issue. Should you have any feedback, questions, or matters you would like us to cover in a future issue, please do not hesitate to write to us at news@breede-river.org. 


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