May 25
The commonest fish in the Little Ouse at #LakenheathFen is #invasivealien European Bitterling, many males, though small, coming into breeding colours & spending a lot of time chasing each other around over the silty, freshwater-mussel-studded, shallows on the river margins. 3/11
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A new occurrence of the #InvasiveAlien ant #BrachyponeraChinensis has been officially reported in Italy via NOTSYS under Reg. 1143/2014.
The report concerns the detection of the species in a new area.
Early warning systems and monitoring are essential to limit further spread.
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16 Jun 2025
On Friday in River Rhône at Chemin du Moulin des Frère, glorious swim (19.6°C) but useless snorkel, almost 0 vis due to inflow from Arve to crystal clear waters flowing from Lake Geneva. Saw only #InvasiveAlien Zebra mussels (dead?), Spiked Water Milfoil & a fish jump #MySwim 1/4
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1 Jun 2025
The Sapiston River/Black Bourn below Ixworth also suffers incredibly dense infestation of #InvasiveAlien Signal Crayfish riddling #river bed & banks with their holes. Another alien is tiny Jenkins Spire-snail (Potamopyrgus antipodarum). At least Great Ram's-horn is native. 5/10
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23 May 2025
This stretch of Cut-Off Channel Wretton had quite a lot River Water-Dropwort (Oenanthe fluviatilis), a few Fan-leaved Water-crowfoot (Ranunculus circinatus), lots #invasivealien Nuttall's Waterweed (Elodea nuttallii) & I wonder if these are leaves of Arrowhead unfurling? 8/15
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21 May 2025
Shocked to find #invasivealien Demon Shrimp (Dikerogammarus haemobaphes). With Cut-off Channel artificially flowing to River Lark, matter of time before it's invaded. It already has Signal Crayfish. Lots bright red Water Mites (Hydrachnidae).
Not sure what insects emerged?
7/25
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21 May 2025
The Cut-Off Channel's clarity - esp. amazing as it's flowing from Great Ouse (during times of flood it flows other way, from the Lark!) - is horrendous infestation of #invasivealien Zebra Mussels (top). How long before they smother the Swollen River Mussels (Unio tumidus).
6/25
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13# Solenopsis invicta🐜, the fire ant🔥 👉europa.eu/!hXcfNC, is an #invasivealien species of Union Concern, native to South America. These ants can build rafts 🛶 when they feel the water level is rising, which could be one reason they spread so much!!‼️️
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22 Sep 2024
Apart from fry, the only animal life I saw in 275 m of River Lark downstream of the noisome inflow, up from Gravel House, was #invasivealien Signal Crayfish.
Upstream, as well as wall to wall fish, there were Painter's Mussels (Unio pictorum). #chalkstreams #WorldRiversDay 3/10
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14 Apr 2024
Good to see plenty Freshwater Shrimps (Gammarus pulex) in River Sapiston/Black Bourn #Ixworth, not good seeing #invasivealien Signal Crayfish.
Lake Sponge (Spongilla lacustris) under rocks & bridge.
On my last 2 swims have seen live Cellar Slugs (Limacus sp) in rivers. Why?
6/9
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17 Sep 2023
Sadly, a high incidence of the Microsporidian parasite, Glugea anomala among the Three-spined Sticklebacks in the Black Bourn & met this feisty little #invasivealien Signal Crayfish at the ford, along with a dead one further down. #Chalkstreams #FakenhamMagna #Suffolk #fish 4/5
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11 Sep 2023
Some fine displays of Lake Sponge (Spongilla lacustris), in hues of green & cream - beneath the surface of the River Thet as it flows past Cloverfields Water Meadows.
Plenty of evidence of Swan Mussels, & much less welcome, #invasivealien Signal Crayfish. #SpongeThursday 10/12
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30 Aug 2023
V v shocked to find infestation of #invasivealien Zebra Mussels in Cut-off Channel at Stoke Ferry aqueduct, incl. killing a Duck Mussel. & a Demon Shrimp? From @NBNAtlas only 2nd shrimp record E of Great Ouse & most Eastern mussel on Cut-off.
What's the "string of beads"?
13/17
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1 Jul 2023
Our assessment of #CumulativeImpacts of #InvasiveAlien species in the #Aegean Sea has just been published. Led by my PhD student Kostas Tsirintanis. Implementing the #CIMPAL approach. mdpi.com/2079-7737/12/7/933
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8 Mar 2023
Great piece by @erikstokstad on extraordinary good news of China's plan to eradicate 90% of #invasivealien Spartina cordgrass from its coastal wetlands by 2025 & input of innovative ultrafast @ConservEvidence global review of what control methods work. science.org/content/article/…
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14 Nov 2022
Amidst the quaggascape of Lake Geneva & further #invasivealien Canadian Waterweed (Elodea canadensis), native plants cling on: Perfoliate Pondweed (Potamogeton perfoliatus), pretty Opposite-leaved Pondweed (Groenlandia densa) & Spiked Water Milfoil (Myriophyllum spicatum).
3/5
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14 Nov 2022
Blissful to swim in crystal clear, warm(ish) water (14.2°C) of Lake Geneva at La Perle du Lac for 30mins, as antidote to a week of @RamsarConv #COP14, but saw not 1 fish & shocked to find it utterly infested with #invasivealien Quagga Mussels.
#MySwim #Geneva #ActForWetlands 1/5
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4 Oct 2022
Along the banks of Wissey Little River at Northwold there's the cloying scent of Himalayan Balsam, an #invasivealien that has severely infested the banks, pretty though it is, with its fun, poppable seed pods. #invasiveplants #InvasiveSpecies #chalkstreams #wildflowerhour
5/8
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2 Oct 2022
On a bright, autumn afternoon @FullersMill, Water Chickweed (Myosoton aquaticum) in bloom on banks, while under stones in River Lark, freshwater sponges & #invasivealien Signal Crayfish lurk. #wildflowerhour #spongethursday #WestStow #Suffolk #Brecks #Breckland #sundayvibes 2/2
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16 Aug 2022
It seems that these crabs discovered in the Gaywood River in Norfolk are not Chinese Mitten Crabs, but the rarer, also damaging, invasive alien species, Asian Shore Crabs (Hemigrapsus sanguineus).
@NorfolkBIS @EnvAgencyAnglia @OuseEcologyEA @echinoblog #nonnative #invasivealien
7 Aug 2022
A🧵on 1st swim in Gaywood River. At request of @RussellB1ggs, had #MySwim at Reffley, then upstream at Derby Fen to clean off. Came biosecure in brand new wetsuits as river maybe Signal Crayfish free. But met another #AlienInvasive, Chinese Mitten Crabs alive & many dead.
1/8
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