Heavy rain and higher river levels could wreak havoc for this years's spawning event!
This spring we have been taking daily river temperatures in an attempt to predict the arrival of the elusive sparling, which typically happens over a few nights between the middle of February and the middle of March. The three main factors influencing the timing and location of the mass spawning event are river temperatures, tide heights and river flows.
Sparling are said to utilise the spring high tides, using the higher tides to reach further up the river to the upper tidal limit. If we look at the predicted high tide heights over the next week they range between 8.5m and 9.3m which could help them migrate. Another element influencing migration is the river temperatures, spawning has been known to occur when river temperatures are around 6°C. This week temperatures have not fallen below 5°C and are slowly rising to reaching that 6°C threshold. So these two factors are lining up quite well however the third factor might delay or impede the spawning this year that would be the river heights.
Quite a bit of rain has fallen in the last few days and by Thursday the Cree has risen by roughly 1.5m. Such high flows could impede the sparling, either forcing them the spawn further downstream closer to the top of the estuary where conditions aren’t ideal or delay the spawning event until lower river levels allow them to migrate further up the river (ideally to the upper tidal limit).
This year to celebrate the rare sparling, GFT hope to host a number of events during the spawning period to showcase this beautiful and rare species. This will hopefully give more people the opportunity to see these amazing silvery fish which smell of cucumbers and learn more about GFTs efforts to conserve this culturally significant species.
We hope to be heading out in the early hours on two occasions (dates to be confirmed) to observe sparling spawning in the hours of darkness, the spectacle has been described as the water boiling with silver flashes. If observing from the riverbanks late at night isn’t your cup of tea feel free to join us aside the new sparling bridge (date to be confirmed) as we hope to display a tank full of sparling for a day if we are able to catch some (river height depending).
The three main events we plan to run are as follows (dates to be confirmed):
Event 1: Night Time Spawning Event Observation (from the river bank)
Event 2: Night Time Spawning Event Observation (from the river bank)
Event 3: Sparling beside the Sparling Bridge
**Please note the elusive nature of the spawning event, triggered by multiple variables, means there is no guarantee that we will be able to observe sparling spawn this spring.
If you would like to attend any events or get involved please contact our Sparling Project Officer Courtney on firstname.lastname@example.org who will email dates in the build-up or follow us on Facebook and Twitter for event updates.
This work is being supported by the Co-op local community fund.