The biology of Welsh sandbanks The Biology of Welsh Sandbanks - In Decline? Mike Camplin Senior Marine Monitoring Ecologist Natural Resources Wales
The biology of Welsh sandbanks Q: What is a sandbank? Answer:.. A raised bank of sand. Habitats Directive Annex I Habitat Sandbanks which are slightly covered by sea water all the time Sandbanks are defined in the Interpretation Manual of European Habitats (EUR 15/2) as: Sandbanks are elevated, elongated permanently submerged and predominantly surrounded by deeper water... consist mainly of sandy sediments water depth is seldom more than 2 m below chart datum... can, however, extend beneath 2 m below chart datum. In other words - A raised bank of sand!
The biology of Welsh sandbanks Where can we find them around Wales? Widespread around the Welsh coastline. Most are marked on Admiralty Charts. This product has been derived, in part, from Crown Copyright Material with the permission of the UK Hydrographic Office and the Controller of Her Majesty's ery Office (www.ukho.gov.uk). All rights reserved.
The biology of Welsh sandbanks More precise extent required for Habitats Directive. Reinterpret existing data Re-interpolation. Re-contouring. Digital elevation modelling. Where can we find them around Wales? This product has been derived, in part, from Crown Copyright Material with the permission of the UK Hydrographic Office and the Controller of Her Majesty's ery Office (www.ukho.gov.uk). All rights reserved.
The biology of Welsh sandbanks Gathering New Bathymetry Data Multibeam Bathymetry Turbot Bank 21 Grassholm Bank 2
The biology of Welsh sandbanks Welsh Sandbanks An updated Annex I sandbank habitat map was completed in 212
The biology of Welsh sandbanks 21 Baseline Survey (SACs) Summary: Infauna 45% annelids 26% crustaceans 16% molluscs 13% others Mobile Epibiota Sandeels Weever fish Brill Sole Rays Common starfish Shrimp, Mysids & amphipods Hermit crab, Swimming crab The true sandbanks were distinct from the others in their biology.
The biology of Welsh sandbanks Sandbank Infaunal Monitoring Two grabs at each station. s spread across the bank in a transect. Some longer banks have two transects A single station on the toe of some banks.
N S H'(loge) Results 28 The biology of Welsh sandbanks Turbot Bank - Species Richness Turbot Bank - Shannon Diversity 7 6 5 4 3 2 1 39 4 41 42 48 49 21 28 4 3.5 3 2.5 2 1.5 1.5 39 4 41 42 48 49 21 28 Turbot Bank - Species Abundance 25 2 15 21 1 28 5 39 4 41 42 48 49
H'(loge) N S Results 29 The biology of Welsh sandbanks Devil's Ridge - Species Richness 14 12 1 8 6 4 2 12 13 14 15 16 21 29 Devil's Ridge - Species Abundance 1 8 6 4 2 21 29 12 13 14 15 16 Devil's Ridge - Shannon Diversity 5 4 3 2 1 21 29 12 13 14 15 16
S S S Results 29 The biology of Welsh sandbanks Devil's Ridge - Species Richness 14 12 1 8 6 4 2 12 13 14 15 16 21 29 Bastram - Species Richness 1 8 6 4 2 21 29 5 51 52 53 54 Tripods - Species Richness 35 3 25 2 15 1 5 11 1 7 8 21 29
S S S Results 212 The biology of Welsh sandbanks Devil's Ridge - Species Richness 14 12 1 8 6 4 2 12 13 14 15 16 21 29 212 Bastram - Species Richness 1 8 6 4 2 21 29 212 5 51 52 53 54 Tripods - Species Richness 7 6 5 4 3 2 1 11 1 7 8 9 21 29 212
The biology of Welsh sandbanks Apparent Decline Investigate Cause CHECK THE DATA! Data handling (analysis) error. No! Methodology change. Yes! Change in grab type 21 (Van Veen) -> 28/9/12 (Day) Change in sampling date 21(July/Aug) -> 28/9 (April), 212 (June) This product has been derived, in part, from Crown Copyright Material with the permission of the UK Hydrographic Office and the Controller of Her Majesty's ery Office (www.ukho.gov.uk). All rights reserved.
The biology of Welsh sandbanks Apparent Decline Investigate Cause Plans for 213 1. Examine data more closely. 2. Repeat sampling using 21 methods (Van Veen grab in mid/late summer). 3. Sample other banks not sampled since 21 to look for similar change. To sample in 213: Turbot Bank (previously sampled in: 21, 28), Helwick Bank (previously sampled in: 21) Bais Bank (previously sampled in: 21 one transect only) This product has been derived, in part, from Crown Copyright Material with the permission of the UK Hydrographic Office and the Controller of Her Majesty's ery Office (www.ukho.gov.uk). All rights reserved.
N N S Closer examination of the data The biology of Welsh sandbanks Consistency of sampling method 29 & 212 both Day Grab samples Should be able to rely on 29-212 changes as there was little methodological difference. (Two month difference, juveniles accounted for). 1 8 6 4 2 Devil's Ridge - Species Richness 12 13 14 15 16 21 29 212 Consistency of taxonomy Aggregating species to higher taxonomic levels did not change the story i.e. differences in taxonomic identification can largely be ruled out. Question remained regarding change from Van Veen to Day grab and late summer to spring/mid summer. 8 7 6 5 4 3 2 1 Devil's Ridge - Species Abundance 12 13 14 15 16 Devil's Ridge - Shannon Diversity 21 29 212 8 7 6 5 4 3 2 1 12 13 14 15 16 21 29 212 21
H'(loge) N S Results 213 The biology of Welsh sandbanks Species Richness 12 1 8 6 4 21 213 2 27 28 29 3 31 32 33 34 35 36 37 38 Species Abundance 16 14 12 1 8 6 4 2 27 28 29 3 31 32 33 34 35 36 37 38 21 213 Shannon Diversity 4 3.5 3 2.5 2 1.5 1.5 27 28 29 3 31 32 33 34 35 36 37 38 21 213
H'(loge) N S Results 213 The biology of Welsh sandbanks Turbot Bank - Species Richness 7 6 5 4 3 2 1 39 4 41 42 48 49 21 28 213 Turbot Bank - Species Abundance 35 3 25 2 15 1 5 39 4 41 42 48 49 21 28 213 Turbot Bank - Shannon Diversity 4 3.5 3 2.5 2 1.5 1.5 39 4 41 42 48 49 21 28 213
N S The biology of Welsh sandbanks Apparent Decline Investigate Cause Change appears real.what caused it? - Widespread not a localised impact. - Whole bank affected, not just the shallower or the deeper stations. So, a widescale influence? To examine Community changed in a similar fashion? Sediment changes? Depth differences (wave action) Compare with other sediment areas (non-sandbank) 2 18 16 14 12 1 8 6 4 2 2 18 16 14 12 1 8 6 4 2 Species Richness The Tripods Bastram Shoals Devil's Ridge Turbot Bank Helwick Bank Sand Bank Species Abundance The Tripods Bastram Shoals Devil's Ridge Turbot Bank Helwick Bank Sand Bank 21 28/9 212/3 21 28/9 212/3 This product has been derived, in part, from Crown Copyright Material with the permission of the UK Hydrographic Office and the Controller of Her Majesty's ery Office (www.ukho.gov.uk). All rights reserved.
The biology of Welsh sandbanks 21-213 Sand Bank Community Change Transform: Square root Resemblance: S17 Bray Curtis similarity 28 213 2D Stress:.9 Bank Helwick Bank Turbot Bank Tripods Devils Ridge Bastram Shoals 212 212 213 212 29 29 29 21 21 21 21 21 Non-metric MDS plot: Year averaged species data for each sand bank.
The biology of Welsh sandbanks Which Species Contributed to Community Change? Group 212 Group 21 Devil s Bank SIMPER 66 Taxa contribute to the 1 st 9% of between year dissimilarity (21-212). Only the first 19 shown here. Species Av.Diss Diss/SD Contrib% Cum.% Av.Abund Av.Abund Bathyporeia pelagica. 19.3 8.66.59 9.55 9.55 Spio armata 6.9 3.6 6.76 1.15 7.45 17. Nephtys cirrosa 1.6 7.3 6.38 1.16 7.3 24.3 Protodriloides chaetifer. 4.5 3.85.44 4.25 28.27 Macrochaeta helgolandica. 3.6 3.59.49 3.95 32.23 Paradoneis ilvana. 3. 3.1 1.16 3.41 35.64 Spio goniocephala. 2.3 2.98.65 3.29 38.93 Thoracophelia flabellifera. 1.7 2.56.63 2.82 41.75 Goodallia triangularis. 2.3 2.17.48 2.39 44.15 Nemertea 1.8 2.2 2.7 1.2 2.28 46.43 Spisula elliptica 1.6 1.1 2.7.77 2.28 48.71 Spiophanes bombyx 2.5 1.5 2.5.54 2.26 5.97 Pseudocuma (Pseudocuma) longicorne.3 2.6 1.97.84 2.17 53.14 Paratyphlotanais microcheles. 1.2 1.88.35 2.7 55.2 Streptosyllis bidentata. 1.9 1.83.72 2.1 57.22 Eurydice. 1.1 1.81.32 1.99 59.21 Scoloplos (Scoloplos) armiger.8 1.9 1.56.56 1.72 6.93 Streptosyllis_Species A. 1. 1.37.63 1.51 62.45 Urothoe elegans. 1.7 1.29.78 1.43 63.87
% Volume % Volume % Volume % Volume The biology of Welsh sandbanks Sediment Granulometry Changes? Devil's Bank Granulometry Batram Shoals Granulometry 8 8 7 7 6 6 5 4 3 Devils Ridge21 Devils Ridge29 Devils Ridge212 5 4 3 Bastram Shoals21 Bastram Shoals29 Bastram Shoals212 2 2 1 1 > 8 mm 4-8 mm 2-4 mm 1-2 5-1 25-5 125-25 63-125 < 63 > 8 mm 4-8 mm 2-4 mm 1-2 5-25-5 125-25 1 63-125 < 63 Grain Size Grain Size Tripods Granulometry Turbot Bank Granulometry 6 8 5 4 3 2 1 Tripods21 Tripods29 Tripods212 7 6 5 4 3 2 1 Turbot Bank21 Turbot Bank28 > 8 mm 4-8 mm 2-4 mm 1-2 5-1 25-5 125-25 63-125 < 63 > 8 mm 4-8 mm 2-4 mm 1-2 5-1 25-5 125-25 63-125 < 63 Grain Size Grain Size
N H'(loge) S The biology of Welsh sandbanks What about the infauna of other sediment habitats? Tremadog Bay, St Bride s Bay & Skomer MNR - Tremadog Bay No apparent decline in diversity measures. Tremadog Bay Diversity 25-212 35 3 25 2 15 S 1 5 25 27 29 21 211 212 Year Tremadog Bay Diversity 25-212 Tremadog Bay Diversity 25-212 12 1 8 4.5 4 3.5 3 6 4 2 25 27 29 21 211 212 N 2.5 2 1.5 1.5 25 27 29 21 211 212 H'(loge) Year Year
The biology of Welsh sandbanks Skomer MNR & St Bride s Bay St Bride s Bay. Two stations five replicates S 16 14 12 1 8 6 4 2 2 28 21 211 212 9 16 N 12 1 8 6 4 9 16 2 2 28 21 211 212 This product has been derived, in part, from Crown Copyright Material with the permission of the UK Hydrographic Office and the Controller of Her Majesty's ery Office (www.ukho.gov.uk). All rights reserved.
The biology of Welsh sandbanks Skomer MNR & St Bride s Bay
The biology of Welsh sandbanks Conclusions There has been a significant reduction in infaunal biodiversity across Wales true sandbanks. The reduction appears real, despite changes in sampling methods and timing. Despite recent changes at Skomer, other sediment habitats do not appear to show a similar pattern of decline. Plenty more questions to ask of the data, but for now, the cause remains a mystery. Any ideas?
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The biology of Welsh sandbanks Sediment Granulometry Changes? > 8 mm 4-8 mm 2-4 mm 1-2 5-1 25-5 125-25 63-125 < 63 Rho Significance Devil's Bank.427 2% Tripods.681 3% Bastram Shoals.631 1% Turbot Bank.62 3% Limited, but significant, degree of correlation between change in community and certain granulometry fractions), but the pattern is different for each sandbank. (BVSTEP PRIMER). ANY DIFFERENCES WITH DEPTH? Yes and no. Some increase in biodiversity loss with reduced depth. Some increase in the shelter of the bank. BUT. No clear pattern across the banks 9 8 7 6 5 4 3 2 1 Helwick1 Helwick2 Devil's Bastram Tripods Turbot B1 S1 T S2 B2