Tees Seals Research Programme

Monitoring Report No.31

(1989 – 2019)

Compiled by Ian Bond

Contents

Summary 3

1. Introduction 4

2. Behaviour 4

3. Monitoring Methods 5

4. Results

4.1. Birth and Survival of Harbour Seal pups 6

4.2. Maximum Count of seals at Seal Sands/ Greatham Creek 7

4.3. Mean Count of seals at Seal Sands / Greatham Creek 8

4.4. Haul-out behaviour at Seal Sands 10

4.5. Greatham Creek 11

4.6 Bailey Bridge 11

4.7 Disturbance 12

4.8 Mortality / infirmity 12

5. Teesmouth seal data outside of the TSRP 13

6. Discussion 13

7. Acknowledgements 14

Appendix 1 – Seal haul-out data at Seal Sands 15

Appendix 2 – Teesmouth Area 22

Appendix 3 – Seal Sands Haul-out Sites 23

Summary

Monitoring this year took place on a total of 47 days. Of these 28 were over the pupping season from mid-June to mid-July, with only one day being missed in that period. Monitoring reverted to the usual practice of a co-ordinated count using two surveyors.

A total of 24 Harbour Seal pups were recorded this year, the highest (by one) ever recorded on Teesmouth. The first pup of the season was born on 19th June, with the highest number of pups being recorded on 10th July. Although no deaths of pups were recorded by the INCA seal monitors around Seaton Channel, the British Divers Marine Life Rescue brought it to our attention that they had dealt with an unprecedented level of pup mortality or infirmity along the coast this year. In total 15 pups were found dead or ill, most of which had similar symptoms.

The maximum recorded number of Harbour Seals this year was 139, which is also a new record high. Oddly the maximum number occurred during the pupping season rather than during the moulting season in August. Mean numbers during the moulting season were also much lower than during the pupping season. Only a small part of this drop in numbers could be attributed to the high level of pup mortality this year.

The mean numbers of Grey Seals across all months was down this year with very few large counts. Nevertheless, some Grey Seals were present on almost 90% of the days during which monitoring occurred, with a maximum of at least 56 animals on 6th August.

The number of recorded disturbances to seals this year was low compared to most recent years and half that of last year. Most of the disturbance was at the Bailey Bridge, caused by bait diggers. Only two instances of disturbance were recorded at Greatham Creek, which was particularly pleasing to note as the recent opening of the England Coastal Path might have been expected to result in more pedestrian traffic across the bridge. It is not unreasonable to assume that the opening of the new viewing facility has played a significant part in reducing disturbance.

Despite the fact that the recorded level of disturbance at Greatham Creek was relatively low this year, the numbers of seals that were recorded as using this location was substantially reduced, being the lowest ever recorded for August.

1. Introduction

Seals have lived at the mouth of the River Tees for hundreds of years, but their numbers had declined rapidly by the late 1800s. This decline would be likely to have been due to a range of factors, with pollution being a main cause. As a result, by the 1930s seals had totally disappeared from the Estuary.

The mid 20th century saw old-style steel and coke plants being replaced by newer, less polluting works. Reclamation of the lower estuary restricted river access and probably reduced disturbance to the seals. From the early 1970s there began a concerted effort by regulators and industry to reduce the pollution load discharged to the estuary. Seals began to reappear and by the 1970s there was again a very small population.

The Tees Seals Research Programme (TSRP) was initiated by the Teesside Development Corporation to monitor the effects of the 1988 phocine distemper virus outbreak on Harbour Seals. Since 1992 the programme has been managed by INCA to monitor the status of the seal population in the Tees Estuary as a general indicator of the health of the River Tees and its intertidal area. This report details the results of this year’s monitoring and compares them to previous results from 1989, thus providing a dataset spanning 30 years.

The TSRP has historically concentrated on Harbour Seal, hence monitoring takes place from mid June to mid September to coincide with the breeding and moulting periods for that species. However, both Harbour and Grey Seals are present in the Tees Estuary and data on both species is collected during this summer period. In addition to the TSRP, INCA has collated a number of casual observations of seals made at Teesmouth throughout the year and these are reported in a separate section of this report. A monitoring programme of seals present at the Tees Barrage is carried out by the Canal & River Trust annually and is the subject of a separate report produced for that organisation.

2. Behaviour

2.1. Breeding

Harbour Seals are the only species of seal to breed on the Tees. They give birth almost exclusively on Seal Sands though at least one birth has been recorded at Greatham Creek. As Seal Sands is only exposed for approximately four hours at each low tide the pups must take to the water shortly after birth. Mother and pup must keep in close contact if the pup is to survive, therefore this is the period when Harbour Seals are most vulnerable to disturbance.

The pups are very small when born, being around 0.7m long and 10kg in weight. They appear very dark in colour, almost black from a distance. Typically, a pup will need to feed for at least 10 minutes in every hour to wean successfully and there is a four-week lactation period during which the pups more than double their birth weight.

With few exceptions the first pup of the season will be born in the third week in June with the remainder of the pups being born over the following three-week period.

The Grey Seal does not breed at Seal Sands. New-born Grey Seal pups, which on the east coast of England, are born around October and November, do not have water-proof fur at birth and do not take to the water until after they are weaned at around three weeks. Therefore, Grey Seal cows give birth above the high water mark and haul out there for long 4 periods of time after giving birth. This is not possible on Seal Sands itself, as haul-out sites are inundated at high tide. The amount of suitable breeding habitat in the wider Teesmouth area would also seem to be very restricted but in theory it is not impossible that a small number of Grey Seals could pup here. As they do not breed locally, most Grey Seals are assumed to leave the River Tees to return to their breeding sites, but it is known that a number remain here throughout the winter.

2.2. Haul-out

Haul-out refers to the period when seals are out of the water. Seal Sands provides an opportunity for seals to haul out during low tide periods but rapidly becomes inundated as the tide comes in. An exception is Area D, which being at the base of an embankment provides an opportunity to haul out for a greater part of the tidal cycle. Conversely Greatham Creek generally becomes unsuitable for seals at low tide as the receding tide leaves a very shallow freshwater channel and the seals risk becoming land-locked until the tide returns. On spring tides, seals typically vacate Greatham Creek around one hour before low tide but on neap tides some seals may stay there over the low tide period. Greatham Creek also provides a haul-out location across the high tide period, although this is not monitored as part of the TSRP. Since 2015, it has been noticed that seals are also hauling out on a small sandbank below the Bailey Bridge, where Greatham Creek joins Seal Sands.

The two species of seal generally haul-out in separate groups. Harbour Seals tend to leave a significant amount of space between individuals, whereas Grey Seals haul-out in a tightly bunched group. However individual Harbour Seals will often be seen hauled out on the periphery of a Grey Seal group and individual Grey Seals within a group of Harbour Seals.

The traditional haul-out location for Grey Seals has been on ‘Site D’ on the south side of Seaton Channel, where it meets Seal Sands, and this is where the largest numbers have been recorded. Conversely it has been rare for even small numbers of Grey Seals to haul out at Greatham Creek. Appendix 2 shows the main areas at Teesmouth that the seals frequent, while Appendix 3 shows the specific haul-out sites used at Seal Sands.

All seals moult once a year and spend a higher proportion of time hauled out then than at other times of the year; consequently this is the time when the highest numbers of adult seals can be counted on land. For Grey Seals, moulting occurs between January and March, compared to the period August through to early September for Harbour Seals.

3. Monitoring Methods

Monitoring during the pupping season began on 14th June before the first pup was expected and continued until 12th July, which was two days after the last pup appeared to have been born. Monitoring was carried out every day except for 30th June (when volunteers were not available), a total of 28 days. During the moulting season, monitoring commenced on 6th August. This is earlier than peak numbers usually occur but the monitoring was brought forward this in year in response to information from the British Divers Marine Life Rescue (BDMLR) that they had recorded significant Harbour Seal pup mortality. Monitoring continued daily for seven successive days but as no seal mortality was observed it then switched to approximately every two to three days until 4th September. In total monitoring was undertaken on 19 days during the moulting season. As the purpose of monitoring during the haul-out season is primarily to record the maximum number of seals, it was considered that the additional information that could be gathered by monitoring each day did not merit the additional volunteer effort that would be required. 5

Counts of seals were carried out simultaneously at Seal Sands and Greatham Creek, with the surveyor at Seal Sands being stationed at the observation hide on the sea wall above Greenabella Marsh (Grid Reference NZ523264) and the surveyor at Greatham Creek stationed on the public footpath on the north side of Greatham Creek (Grid Reference NZ509256).

Counts at Seal Sands took place every 30 minutes, for 90 minutes hours either side of low tide, giving seven counts per day. At Greatham Creek counts took place every 30 minutes from 90 minutes before low tide to low tide, except for neap tides when counts at Greatham Creek continued for the full three hours (on a neap tide seals may remain at Greatham Creek throughout the tidal cycle but otherwise have vacated it by low tide). Counts were therefore synchronised for the period when seals were expected to be present at both Seal Sands and Greatham Creek. In between each 30-minute synchronised count, the surveyor at Greatham Creek walked the 600m to the Bailey Bridge (Grid Reference NZ515255) and counted any seals hauled out there. The counts at the Bailey Bridge continued for the full three hour period. Up to 2017 the counts had taken place over the four hour period around low tide; however, the numbers of seals hauled out is notably lower two hours outside of low tide, so it was considered that there was little to be gained from continuing that additional volunteer effort.

The following information was recorded at each of the 30-minute counts on each day: • Numbers of each species; • The locations where the seals were hauled out; • The number of pups.

In addition, a record was made of the following during the whole of the three-hour count: • Instances of disturbance to seals; • Deaths or injuries to seals; • Abandonment of pups; • Notable features of behavioural, e.g. species interactions; • Weather conditions.

4. Results

4.1. Birth and survival of Harbour Seal pups

A total of 24 pups were recorded in 2019. This is the highest number ever recorded as being born at Teesmouth. The first pup was born on 19th June, one day later than in the previous two years. The highest count of pups was made on 10th July, three days later than the previous two years. As pups swim off with their mothers within hours of birth, it is not possible to track individual pups and not all might haul out on each tide, therefore the total recorded is the minimum number of pups born. The date when the highest number of pups is recorded is taken to represent the date of the last pup birth, unless observations clearly suggest otherwise.

No mortality of pups was recorded during the TSRP monitoring period, which for most pups would cover the period when they were dependent on their mothers. However, on 26th July the BDMLR reported that they had picked up eight dead Harbour Seal pups locally. These appeared to have contracted a similar infection. A ninth pup was alive but in rehabilitation and a further pup had been killed, allegedly by a group of youths, on the beach at Crimdon. A further three pups were picked up by the BDMLR over the following weekend. In total this 6 year 14 Harbour Seal pups were picked up between Sandsend and Tynemouth. As the Teesmouth Harbour Seal colony is the closest to both of those locations it is likely that the seal pups all originated from Teesmouth. A fifteenth pup found at Bridlington may have come from a colony on the Lincolnshire coast but could in theory have come from Teesmouth. This last seal pup was successfully rehabilitated but the BDMLR were unable to confirm how many, if any, of the other pups survived. In September another pup was found dead by INCA staff at Bran Sands; it was well grown but still would have been from this year. In total then it is possible that as many as 15 of our Harbour Seal pups may have died this year.

Figure 1 shows the birth and survival rates of Harbour Seal pups at Seal Sands since the inception of the seal monitoring project. The mortality for this year would seem to be dramatic, but it should be noted that pup mortality during post-weaning periods is likely to be quite high in every year. Had we not had information from BDMLR for the first time this year and Figure 1 just reflected TSRP data, then the mortality shown in the graph would be have been zero.

Figure 1: Harbour Seal Birth Rate (1989 – 2019)

4.2. Maximum Count of Seals across Seal Sands / Greatham Creek

Maximum numbers of each species of seal recorded in 2019 are compared with the corresponding figure from previous years in Figure 2. The maximum numbers are the aggregated results of simultaneous counts of all seals at Seal Sands, Greatham Creek and the Bailey Bridge and represent the maximum number of each species seen hauled-out at any one time over the entire survey period.

Figure 2: Maximum Number of Seals Recorded (1989 – 2019)

The highest maximum count of Harbour Seals in 2019 was of 139 individuals on 10th July. This is also the date this year when the highest number of Harbour Seal pups was recorded, which meant that 115 of the 139 were adults. The highest maximum count in 2018 also occurred on the same day as the highest number of seal pups was recorded. Pups would be expected to make a higher contribution to the total numbers while they are with their mothers than after weaning (when mortality is likely to increase). Nevertheless, it would be expected that the maximum counts of Harbour Seals would be in August and September during the moulting season, as has been the case in previous years. The highest count of Harbour Seals during the moulting season this year was of 118 individuals on 8th August.

The highest maximum count of Grey Seals in 2019 was of a minimum of 56 individuals on 6th August. Of these, 15 were on Seal Sands and 40+ on Site D. As has been pointed out in previous reports it is not possible to accurately count the number of seals on Site D from the Seal Hide once they exceed about 20 individuals. On one occasion a count of 40+ made from the Seal Hide proved to be only half the number counted from a closer vantage point. Counts of Grey Seals that include a large contribution from Site D are therefore always assumed to be a broad approximation.

The highest total number of seals hauled out at any one time was at least 170, again on 10th July, when 31 or more Grey Seals added to the maximum number of Harbour Seals. Total numbers in excess of 150 seals were also recorded on 6th and 7th August.

4.3. Mean Count across Seal Sands / Greatham Creek

The mean number of both species of seals across all haul out sites at Teesmouth was calculated for the months of the June, July and August. A mean has not been calculated for September this year as only a single count was undertaken. As in the two previous years,

8 but in contrast to all years prior to 2017, monitoring only occurred during the first half of July. In addition, for the past three years counts in August have not been made throughout the entire month. The figures from 2017 onwards may therefore not be directly comparable with earlier years, as the timing of moulting and therefore the peak haul-out numbers may change slightly from year to year.

4.3.1. Harbour Seal

The mean number of Harbour Seal observed was 64 for June; 105 for July and 76 for August. Mean numbers for June was broadly in keeping with those of recent years but the mean for July was a 50 per cent increase on the previous highest mean. By contrast, with the exception of 2018 when the survey methodology differed from all other years, the August mean was the lowest since 2013.

Figure 3: Mean Harbour Seal Count from June to September (1989 – 2018)

4.3.2. Grey Seal

The mean number of Grey Seal observed was 13.0 for June; 11.0 for July and 14.0 for August. These are the lowest figures since 2011 for July and since 2009 for June and August, and constitute around half of the mean numbers recorded in recent years. This is despite their being four counts of 40 or more animals. Nevertheless, some Grey Seals were nearly always present, being unrecorded on only six days out of the 45 days when monitoring took place.

Figure 4: Mean Grey Seal Count from June to August (2005 – 2019)

4.4. Haul-out Behaviour at Seal Sands

Site usage at Seal Sands is dependent upon the height of the low tide. The elevation of Site ‘A’ is relatively high in comparison with most of the other haul-out sites (except Site ‘D’, which is exposed for most of the tidal cycle). Site ‘B’, Site ‘C’, the ‘Spit’ and the ‘Wall’ are only 2.3m above the Lowest Astronomical Tide (LAT), so on a low neap tide they are almost covered by water. Typically, sites ‘A’, ‘B’, ‘E’ and the ‘Wall’ are used mainly by Harbour Seals, while Site ‘D’ is used by Grey Seals, with Site ‘C’ and the ‘Spit’ being used by both species.

As is usually the case, in 2019 most Harbour Seals hauled out at Site ‘A’, with very few hauled out at Site ‘B’. At Site ‘C’ the trend of much lower numbers hauling out there in recent years continued. On the ‘Spit’, mean numbers of Harbours were seven in June and July but 40 in August. A similar, though less extreme, monthly pattern occurred in previous years and may be related to the seals hauling out further from the main channel during the pupping season.

The figures for the mean use of Site D by Grey Seals are well down on previous years for June and July and up slightly for August. The mean numbers present something of a distorted picture though, as Greys were only present at Site D on two days in each of June and July. In August they were only present on three days but on each day in excess of 40 animals were present.

Graphs showing the usage of the various sites over the years are provided in Appendix 1.

4.5 Greatham Creek

Since the commencement of counts at Greatham Creek it has been the mean number of Harbour Seals hauled out in August that has been used to compare years. This is shown in Figure 12. The mean over that period this year was 18.4, which is the lowest number since records began and less than half the mean for 2017. The maximum number this year was 69 and this is also well below maxima in recent years.

The number of Harbour Seals present at Greatham Creek during the pupping season has not been collated for previous years, except for 2018. This year the mean number over that period was 10, compared to 15.6 in 2018.

Grey Seal presence was confined to a single individual in the June/July survey period and on five occasions in August. One of the August counts was of 11 individuals which is exceptional for a low tide count at Greatham Creek.

Figure 12. (NB The number of seals hauled out in August was not recorded separately from the total number in 2018 so that year is omitted.

4.6 Bailey Bridge

The Bailey Bridge site is a sandflat on the south side of Greatham Creek, immediately upstream of its outflow onto Seal Sands. It is a little under 0.2ha in extent at low tide and is located slightly higher in the tidal frame than most of Seal Sands. Harbour Seals were recorded hauling out at the Bailey Bridge on only five days during the pupping season, which was the same number as in 2018. There was a peak count of seven animals and a mean of 0.5. This contrasts quite markedly with the moulting season when Harbour Seals were hauled out on 11 of the 17 survey days with a maximum count of 18 and a mean of 5.5. Grey Seals were not observed hauling out at the Bailey Bridge. The extent to which the Bailey Bridge is used as a haul-out would appear to be restricted by disturbance (see Section 4.7).

4.7 Disturbance

The TSRP records any instances of disturbance to seals so that the information could be used to inform any remedial actions that might be necessary. The term ‘disturbance’ can relate to any observed adverse reaction of seals to a stimulus, not just to seals taking to the water. It is particularly important to avoid disturbance to Harbour Seals when there are dependent pups, since separation of mother and pup could cause abandonment and the subsequent death of the pup.

A total of eight instances of disturbance were recorded in 2019, of which half were at the Bailey Bridge. One of these was by a group of walkers with the other three being caused by bait diggers. On a further five occasions, bait diggers were noted as being present at the Bailey Bridge and no seals were present. That does not of course mean that seals would have been hauled out had the bait diggers not been there, but on one occasion six seals were noted as hauled out there within minutes of the bait diggers leaving.

There were two instances where seals entered the water in response to a passing boat, one on Seal Sands and one at Site D. Only two instances of disturbance were recorded at Greatham Creek. One of these was by people on the mudflat, the other by people on the road bridge.

Notwithstanding that the activity of bait diggers might be limiting the use of the Bailey Bridge as a haul-out, the levels of disturbance recorded this year were low compared to most recent years and half that of 2018.

It is particularly welcome to note that only one instance of disturbance was recorded from the A178 road bridge. The western side of the road bridge, overlooking the seal haul out, now forms part of the England Coastal Path. This raised concerns that it might result in increased disturbance to the seals; fortunately this appears not to have been the case. In 2018, levels of disturbance were much higher and around half of all disturbances were caused by people trying to see the seals at Greatham Creek. In the intervening period, a new viewing facility has been installed at Greatham Creek and an expanded car park provided to the south. The presence of such improved visitor infrastructure certainly correlates with a reduction in observed disturbance.

4.8. Mortality / infirmity

The high level of pup mortality this year has been described in section 4.1. As of the date of production of this report we have no information as to whether the cause of death of the pups which showed similar symptoms, notably swelling of the mouth, has been ascertained.

Otherwise we are aware of few instances of mortality or infirmity. A young Grey Seal, which would have been a pup born in 2018, was found stranded on the top of the sea wall at Redcar in March. It was rescued by BDMLR and checked by Saltburn Vets before being released at South Gare.

A dead female grey seal that was found at Seaton Snook in May had been tagged as a pup on the 15th November 1993 in the Farnes so had lived to a good age.

Two seals were reported as being washed up dead near to Steetley Pier in Hartlepool in early December, but they had disappeared before they could be collected or identified. 12

5. Seal data outside of the Tees Seals Research Programme

A total of nine counts of seals on Seals Sands at the period around low tide were carried out between 6th December 2018 and 20th March 2019, with all but one being undertaken by INCA staff. The number of seals that were hauled out varied from seven to 32 with a mean of 21. Of the eight counts carried out by INCA when the species were differentiated, Grey Seals were only present on one occasion and then only two animals. The mean number of Harbour Seals was very similar to the mean number recorded in a more extensive series of counts at Seal Sands in winter 2017/18.

Across the year from November 2018 to November 2019, a total of nine seal counts were carried out at Greatham Creek at high or mid tides. Harbour Seals were present on all occasions and averaged 30 animals. Grey Seals were present on at least four of those occasions with a maximum of 12 individuals and a mean of almost three. Of the four Grey Seals that were present on 6th November 2019, two were mature bulls, which was surprising as that was the peak of the mating season and mature bulls would be expected to be at their breeding sites. As with previous years these anecdotal records indicate that more seals haul out at Greatham Creek at high or mid tides than during the three-hour period around low tide that is monitored through the TSRP.

The completion of the Greatham South managed realignment scheme has created a large pool to the south of Greatham Creek and it appears that this is regularly used as a haul out by small numbers of Harbour Seal. It was also noticed in November 2019 that some Harbour Seals were hauled out much further up Greatham Creek than usual, over a kilometre upstream. If this becomes a regular feature of their behaviour, then it will make it difficult to obtain an accurate count of seals at Greatham Creek.

6. Discussion

This year set another record for the maximum number of Harbour Seals counted and for the number of seal pups born. This further suggests that the dip in the maximum count in 2018, which bucked the decade long trend of gradually increasing numbers, might have been due to changing the methodology for the counts in the moulting season in 2018 to just one surveyor covering all sites.

Despite the record numbers, the most noticeable feature of this year was the high level of pup mortality. It is a typical feature of mammalian life histories that mortality immediately after weaning is high, so as pointed out in Section 4.1, pup mortality is likely to be high in any given year. The reason that the TSRP usually records such little pup mortality is likely to be due to infirm or dead seal pups not necessarily washing up in Seaton Channel where the monitoring takes place. As far as we are aware all the seal pups picked up by the BDMLR this year were along the open coast. Despite the likelihood that pup mortality in any given year will be significantly higher than that recorded by the TSRP, the BDMLR did indicate that this had been an exceptional year for pup mortality.

No adult seal mortality was recorded by the TSRP nor, as far as we are aware, was it by the BDMLR. It was therefore surprising that the maximum number of Harbour Seals counted in late August, during what should have been the peak of the moulting season, was only 114, compared to 139 in early July. The early July figures included pups so this could in part be explained by the pup mortality, but not all pups died so it appears that there has been some loss of adult seals. This loss could however be down to emigration rather than mortality. A similar pattern of reduced numbers during the moulting season compared to the pupping 13 season occurred in 2018, but as pointed out above this may have resulted from the different methodology.

The other notable feature of 2019 was the reduced number of Harbour Seals that were counted at Greatham Creek. Average numbers in August were around half that of recent years and the maximum number recorded was also substantially lower. This is unlikely to be due - at least primarily - to the lower numbers counted in the estuary in August, as that was still a higher maximum number than any count prior to 2015. Furthermore, numbers counted at Greatham Creek during the pupping season this year were only around two thirds of those counted over the same period in 2018. One possible explanation is that some seals may be hauling out at other parts of Greatham Creek, as was noted later in the year (see Section 5, above). As such these animals may have been missed by the seal monitors recording from the traditional location. However, the limited amount of evidence gathered so far would indicate that even if this was the case it only involves a few individuals, so is unlikely to have reduced recorded numbers to anything like the extent that has been observed this year.

7. Acknowledgements

This ongoing project would not be possible without the support of Venator (formerly Huntsman Pigments) who provide the observation hide and security arrangements for the seal monitors.

The raw data for this report is collected by a dedicated team of monitors. Particular thanks are due to Linda Watson, the co-ordinator of the group. In addition, in 2019 the monitors were; Dave Thew, Dennis Ncube, Dez Watson, Jacob Noel, Louise Howe, Mel Watson and Terry Wells.

We are very grateful to Daniel Fox of the British Divers Marine Life Rescue for bringing the issue of the Harbour Seal pup mortality to our attention and for providing us with information on numbers and locations.

Unless otherwise stated, the images displayed in this document are INCA copyright or reproduced with permission of the copyright holder. The images are not to be reproduced without the express permission of INCA. Any maps or location plans in this document have been reproduced in accordance with INCA’s licence from the Ordnance Survey.

Appendix 1. Seal haul out data at Seal Sands.

The following data give a summary of monthly, mean numbers of both Harbour and Grey Seal observed over the three-hour low tide period at each of the haul-out sites on Seal Sands. Monthly means were obtained using the maximum numbers of seals present on each site during the low tide period on the days where monitoring took place. Comparative data from the period 2007 to 2018 is shown in the charts in Figures 5-11, to place the 2019 data into context. No data on individual haul-out sites was collected for August 2018. Since 2016 data has not been obtained for September; charts illustrating the data for September for the period 2008 to 2016 can be found in the 2016 TSRP report. The bar charts below show blue columns corresponding to the average number of Harbour Seals, while red columns correspond to the number of Grey Seals. The location of the named sites (Site ‘A’, ‘B’, etc) are shown in Appendix 2.

Figure 5a: ‘Site A’ June 2007-2019

Figure 5b: ‘Site A’ July 2007-2019

Figure 5c: ‘Site A’ August 2007-2019 15

Figure 6a: ‘Site B’ June 2007-2019

Figure 6b: ‘Site B’ July 2007-2019

Figure 6c: ‘Site B’ August 2007-2019

Figure 7a: ‘Site C’ June 2007-2019

Figure 7b: ‘Site C’ July 2007-2019

Figure 7c: ‘Site C’ August 2007-2019

Figure 8a: ‘The Spit’ June 2007-2019

Figure 8b ‘The Spit’ July 2007-2019

Figure 8c ‘The Spit’ August 2007-2019

Figure 9a: ‘The Wall’ June 2007-2019

Figure 9b: ‘ The Wall’ July 2007-2019

Figure 9c: ‘ The Wall’ August 2007-2019

Figure 10a: ‘ Site D’ June 2007-2019

Figure 10b: ‘ Site D’ July 2007-2019

Figure 10c: ‘ Site D’ August 2007-2019

Figure 11a: ‘Site E’ June 2007-2019

Figure 11b: ‘ Site E’ July 2007-2019

Figure 11c: ‘ Site E’ August 2007-2019

APPENDIX 2: Locations within the Tees estuary

Greatham Creek (including ‘managed realignment scheme’)

Seal Sands

Bailey Bridge

APPENDIX 3: Location of haul-out sites on Seal Sands

Observation Point

Site D

The Spit

Site C

Site B The Wall

Site E

Site A

210 105 0 210 Meters