Update on water plant management at Hickling Broad

A key aspect of the Broads Authority’s work is to balance the recreational and ecological importance of the waterways it manages. 

A perfect example of this appeared in June this year, when a survey of water plants was carried out over Hickling Broad to help sailors understand where plant growth was thickest.

A state of art hydroacoustic surveying and mapping system was used to discern the density and distribution of submerged water plants in the area. The findings can be seen outlined on the map.

Hickling Broad hydroacoustic survey findings

Depicted are the findings of the survey, illustrating that the marked channel is free from water plant growth as is the large central portion of the Broad, -good news for boat users. However, the area of broad that is covered in plant life has increased to an even healthier level, with rare species such as stonewort vastly improved in numbers. This density of plant growth subsequently has very positive benefits for water quality and associated fish and bird life.

With the total amount of water plants increasing, it is key that this diversity of plant life is sustainably managed. The Authority is working to relieve some of the issues sailors have experienced outside the marked channel, but within protective thresholds to maintain the harmony between navigational access and the flora of the area.

Balancing these two integral aspects of the Broads National Park is a priority for the Broads Authority. To guarantee access to businesses and local amenities, the Authority has gained permission from Natural England to maintain the clear navigational access within the marked channel. As a result, in early July 2017 the Broads Authority deployed its weed harvester to manage the area. This will be able to return through the season, as required.

Areas that have been identified as of particular significance to the sailing community have been granted a further precautionary 5% cut back in recognition of the areas recreational importance. The water plants that can be cut are the more common species of fennel leaved pondweed and spiked water milfoil. The precise location of the cutting to be carried out before the end of July has been agreed with local members of the sailing community, who know best where the prime areas for boat users are situated.

From a conservation view point, the exciting arrival of stonewort in 60% of water plant sample points means that it is time to start a trial into understanding the effects of management on this variety of water quality enhancing plant. Trial cut backs and a meticulous monitoring program are set to help understand the long term impact of cutting activity on the growth, reproduction and survival of this important Broadland plant.

Tuesday 25 July 2017