From June 7-10, Matilde Trambajolo (vet intern) and Anna Salazar Casals (vet) attended the Zoo and Wildlife Health conference 2023, which took place in Valencia.

As the organisers mentioned: "This conference provides a unique platform for members of the veterinary community, wildlife enthusiasts and conservationists from all over the world, to come together, discuss, and exchange knowledge on various issues, including the latest advancements in research and best practices in wildlife conservation, veterinary medicine, and animal welfare. As we continue to confront a rapidly changing world of emerging diseases, habitat loss, and climate change, the work of zoo and wildlife veterinarians is more important than ever. Our profession plays a crucial role in both the conservation of endangered species and the protection and well-being of the animals under our care. Our commitment, expertise, and insights are invaluable resources for the broader scientific community, policymakers, and the public."

The conference was very interesting, the content very nice and informative, and the people very nice and willing to learn and collaborate.

Matilde presented a project she did for her master thesis at Barcelona Zoo. This project looked at antibiotic resistances within the zoo. She looked at different samples from different animals and checked for antimicrobial resistance. Matilde presented her results and answered all the questions asked by the public in a calm and professional way. She was confident in herself and presented very well. This is the summary of her presentation:

"The potential for emergence of antibiotic resistance (AR) in zoo settings poses a challenge to the adequate treatment of individuals and a potential threat to public health. This retrospective study aimed to characterize AR in mammals kept at Barcelona Zoo between 2016-2021. Bacterial cultures (n=1026) were recovered from clinical records, of which 29% were positive with available antibiograms (n=298). Of these, 238 antibiograms were selected according to a “first-bacterial-genus-per-isolate-per-patient” methodology, mostly from Bovidae (n=63), Delphinidae (n=41) and Hominidae (n=32). AR was assessed including yearly multidrug resistance (MDR) occurrence (i.e., bacteria resistant to three or more antibiotic classes)a, generation of a cumulative antibiogram (CA) (i.e., susceptibility rate of the ten most isolated bacteria to the ten most used antibiotics)b,c, and non susceptibility trends for selected pathogens. The most frequently isolated bacteria were Escherichia spp. (n=78), Pseudomonas spp. (n=44) and Staphylococcus spp. (n=42). Yearly MDR rates oscillated between 28% (9/32 isolates, 2018) and 72% (13/18, 2016; 20/28, 2019), without evolution identified. The CA revealed low susceptibility rates of most Gram-negative bacteria to ampicillin (0-70%; x̄=15%) and cefalexin (13-81%; x̄=35%). Likewise, Pseudomonas spp. presented low susceptibility rates to numerous antibiotics (0-86%; x̄=43%). Annual non-susceptibility rates significantly decreased for Escherichia but increased for Pseudomonas and Enterococcaceae (p<0.05). Overall, AR was demonstrated for bacterial isolates at Barcelona Zoo, underscoring the need for a rational use of antibiotics. Furthermore, this study highlights how CA can serve as a guide to empirical prescriptions when cautiously elaborated and interpreted."

Anna presented the results of the article published in August 2022 about seal entanglements. The public was very happy with the content of the talk and were surprised with the results Anna showed. This is the summary of Anna's presentation: "In recent decades, the amount of marine debris in our oceans has increased, leading to more interactions between debris and animals. Increased interactions consequently lead to more entanglements, modifying an animal’s normal behaviour and potentially affecting its survival. The current study collected information on two phocid species, harbour (Phoca vitulina) and grey seals (Halichoerus grypus), that were affected by marine debris over 11 years (2010-2020), along the Dutch coast (n=145). The data includes strandings and sightings of live and dead animals reported to one of the three Dutch seal rehabilitation centres. The results of our study show that: (i) the number of entangled seals has quadrupled over the study period, (ii) 67% of the entangled animals were juveniles, (iii) the number of entangled grey seals was more than 4 times higher than that of harbour seals, whereas harbour seals were more likely to ingest debris, and (iv) 88% of the debris causing entanglements came from the fishing/boating industry. The species differences we found can be explained by differences in their behaviour, their foraging strategies, and their habitat preferences. There was no consensus when reporting lesions or entangling material, hence no further analysis was possible. Future research in this field will enormously benefit from standardizing data collection and for this purpose we present a new detailed stranding form. Despite increased public awareness about the adverse environmental effects of marine debris, more initiatives and policies are needed to ensure the protection of the marine environment in the Netherlands."

Thanks to this conference, both Matilde and Anna have managed to connect with many veterinarians van around the world and spread the word about the work done by and at Sealcentre Pieterburen. Furthermore, several veterinary students from many European Universities attended this conference and were interested in our educational programs, both in the veterinary and sealcare departments.

From selfies to throwing stones, seal pups find nowhere to rest

Sealcentre Pieterburen has experienced far too many cases of disturbed seal pups in the past two weeks. In the past few weeks, 33 seal pups have been taken care of at seal centre Pieterburen. Of these, 10, a third of all cases, arguably ended up at the centre due to actions by the public. The centre stresses again that due to the Seal Agreement signed in 2020, this is strictly forbidden.

Moreover, touching seals, even small pups, is actually not without danger. They are the largest predators in the Netherlands. Seals have a powerful bite that can lead to severe inflammation in humans. A seal bite has to be treated with special antibiotics. In two cases, pups were placed in the arms of children for a photo. A big risk for both humans and animals.

On 4 June 2020, the Seal Agreement was signed and became effective. This agreement aims to prevent the rehabilitation of seals by increasing the use of observation and relocation. For example, it is common for pups to spend hours alone when the mother is out hunting. This has also emerged from previous behavioural research on seals (mothers) in the Dollard. Pups sometimes lie alone for up to 8 hours, with no ill effects. So a pup lying alone is not always in distress and should be left alone. Finally, the agreement also states that for the animal's safety, as well as that of humans, it is forbidden to take action on their own. Only certified seal guards are allowed to do so and are in close contact with the centre in whose area they operate. It is up to the rehabilitation centres to decide whether a seal should be taken in or not.

De bouw van het Werelderfgoedcentrum in Lauwersoog is in volle gang. Op dit moment wordt er hard gewerkt aan de fundering van het gebouw. Een onderdeel daarvan is het gieten van beton. Voor zo’n groot gebouw is daar een hoop voor nodig. Gister was er zelfs een file aan betonvrachtwagens om het af te leveren. Bekijk hier de timelapse van de voortgang van afgelopen weken: http://timelapsebot.netcamviewer.nl/download/NCVTimelapser_CID_1437_PID_image_PSN_image_2023-06-01_06-18-37-1686142474.mp4 

Wil je de werkzaamheden van het Werelderfgoedcentrum op de voet volgen? Dit kan via de BouwApp!

Sealcentre Pieterburen has taken in the first common seal pup of this summer. The animal had been found by bystanders. They saw no mother around and thought it needed help. The Sealcentre would like to remind everyone that it is forbidden to touch seals except for trained seal guards. This is the only way operational seal centres can pursue the policy according to the Seal Agreement.

On Friday afternoon 19 May, bystanders came across a common seal pup near Sint Jacobiparochie. This one was lying alone in the mud with no mother around. As it was a young animal, the bystanders assumed it could not take care of itself. Therefore, they decided to take the pup with them. They then called Sealcentre Pieterburen to seek professional help.

While the Sealcentre understands the good intentions, this is not the desired course of action. Picking up and helping seals yourself is contrary to the policy set out in the 2020 Seal Agreement . This agreement puts the focus on observing wild seals before deciding whether rehabilitation is needed. Therefore, there are trained seal guards who monitor reported animals and relay all necessary information to the seal centre for which they operate. The centre then decides whether to take a seal to the centre. This way gives the most certainty that rehabilitation was the right choice. If the public decides to intervene themselves, it becomes impossible for seal centres to pursue this policy.

A seal mother can leave her pup alone for up to eight hours, without anything needing to be wrong. Unfortunately, the pup was too severely disturbed to be returned to the area she came from. It was therefore decided to take the animal in. Once in Pieterburen, she was given the name Crista. This name is derived from the scientific name for the hooded seal, Cystophora cristata. A species of seal not normally found in the Netherlands, but which gave birth to a young on Vlieland in March this year. A unique event and therefore the inspiration for the name of the first pup this summer. She was probably at most six days old and born prematurely. This makes her still very weak and she is therefore closely monitored by the vets and intensively cared for. The pup can currently be admired from a safe distance at the Seal Centre.

The first pup marks the start of the common seal's birthing season. Many pups will be born in the coming period and receive milk from their mothers for about three to four weeks. All seal centres and seal guards therefore continue to appeal to keep as much distance as possible from seals at this time in particular, so that mother and pup can pass this suckling period undisturbed. If people still have doubts about the health of an animal, they should report it via 144 (available 24 hours a day). After being reported, seals are observed for at least 24 hours, as research shows that many seals can handle themselves well - provided they get enough rest during those 24 hours. Seal guards can ensure this by cordoning off areas and informing the public, while staying in touch with seal centres about the animal's condition.

Last Sunday, Cornelia was released! This adult grey seal came to us weakened on 21 February. And now she is strong enough again to return to the Wadden Sea. Together with other grey seals, she was released. It was a beautiful release at sunset.

Het gebeurt niet vaak dat we een volwassen grijze zeehond in de opvang hebben. Vrijwilliger Martina Zilian heeft mooie foto’s van haar gemaakt. 

De geboorte van een klapmuts op Vlieland was bijzonder nieuws. Onze collega Sander van Dijk was uitgenodigd bij het tv programma Tijd voor Max om meer te vertellen over de deze zeehondensoort. Hij had onder andere een schedel van klapmuts meegenomen om te laten zien aan de kijkers. Ook was Gerard Koster Joenje van vlielandplaatjes.nl erbij om wat mooie beelden te laten zien. De onderstaande afbeeldingen zijn ook van Gerard. 

Bekijk here het fragment.

On the morning of Monday 27 March, a hooded seal gave birth to a pup on the beach of Vlieland. The hooded seal is a seal species that occurs naturally around the polar region, so that makes this very exceptional and special. After consultation with Sealcentre Pieterburen and the local seal guard, police and army have closed the area to the public for the time being. However, this is of limited duration and the centre is concerned about long-term conditions for the pup. Therefore, the centre calls for the animals to rest.

On Monday 27 March, seal guard Willem made a very special discovery on the beach of Vlieland: a hooded seal that had recently given birth to a pup on the beach of Vlieland. Never before had this occurred. Hooded seals are native to the polar region and have one of the shortest nursing periods of all seal species: only four days on average. Therefore, the we are so gratefull that the local police and the army closed off the area around the mother and pup for the time being. Hopefully, the two will be able to get through the suckling period undisturbed.

The short suckling period will be followed by a period of fasting for the young animal, during which it will occasionally ingest some fluids through the ice it normally lies on. Then the animal goes hunting in the open waters of the polar region. These conditions are obviously lacking here. The centre is therefore concerned about how the pup will fare afterwards. Either way, it will be important to give the animals rest, and the centre makes the appeal to do so. Moreover, it is working with police and army to find a solution to keep the area closed for longer.

The hooded seal is a seal species listed as "vulnerable" on the IUCN red list. They live mainly around Greenland. Every now and then, young animals sometimes end up elsewhere. Several hooded seals have also been taken in the Netherlands, but 3 times in the past 10 years. In 2013, a young hooded seal came into Sealcentre Pieterburen and in 2014 and 2018 at A Seal in Stellendam.

Photo credit: Gerard Koster Joenje, vlielandplaatjes.nl

Ana, onze Hoofd Dierengeneeskunde, Zorg & Wetenschap en Sara, Stagiare Dierenarts woonden deze week de conferentie van de European Association of Aquatic Mammals (EAAM) bij. Beiden gaven een presentatie over hun onderzoek, gebruikte methoden en eerste bevindingen. Dat Ana en Sara het Zeehondencentrum vertegenwoordigen op de conferentie voor het welzijn en behoud van zeezoogdieren door middel van onderzoek, medische zorg, opleiding, onderwijs, behoud, beheer en activiteiten – dáár zijn we erg trots op!

Congenital disorders in harbour (Phoca vitulina) and grey seals (Halichoerus grypus) admitted into rehabilitation from the Dutch Wadden sea 

Congenital disorders are functional or structural defects that are present at birth. Monitoring of birth defects in wildlife can provide conservationists with information about the status of that population and can help with the detection of emerging teratogens. In marine mammals, there are few reports on congenital abnormalities, which are mostly found during postmortem examinations. 

Harbour (Phoca vitulina) and grey seal (Halichoerus grypus) populations of the Dutch Wadden sea are stable and considered healthy. The current study summarizes information on sporadically appearing congenital or potentially congenital abnormalities in harbour and grey seals between 2014 and 2022. All animals were admitted into rehabilitation at Sealcentre, Pieterburen, in The Netherlands. We focused on the diagnostic methods and outcomes of each individual. The diagnoses were based on physical examination, clinical symptoms, and diagnostic imaging. These cases included melanism, albinism, microphthalmia, esophageal stenosis, impaired swallowing reflex, vestibular disease, dwarfism, hiatal hernia, cleft lip, arthrogryposis, and megaesophagus. During the study period, a total of 2739 seals were admitted into rehabilitation. The prevalence of congenital disease in our study was 0.62%. 

Gut microbiome of stranded harbour seals (Phoca vitulina) admitted for rehabilitation. 

In the Netherlands, the Sealcentre Pieterburen rehabilitates an average of 250 grey seals (Halichoerus grypus) and harbour seals (Phoca vitulina) per year. Being held in temporal captivity for rehabilitation might have an effect on the seals microbiome, and our study aimed to understand this effect in the gut microbiome of stranded harbour seals and the main factors contributing to it. We investigated the distal gut microbiome of two large cohorts (pups and weaners) of stranded harbour seals that were admitted for rehabilitation at the Sealcentre. The gut microbiome of young harbour seals stranded in the Netherlands is composed of Proteobacteria, Firmicutes, Bacteroidota, Fusobacteriota, Campylobacterota, and Actinobacteriota, and corresponds with the main core phyla described for this species in other parts of the world. The alpha diversity (richness and Shannon diversity) of the pup’s microbiome increased significantly during rehabilitation, while there were no significant changes in the weaners. Beta diversity of both pups’ and weaners’ gut microbiome was different before and after rehabilitation, with age and sex as main factors. We conclude that there was an important change in the microbiome of stranded harbour seals that were admitted to the Sealcentre.

Ana Rubio-Garcia1*, Aldert L. Zomer2 , Ruoshui Guo2, John W.A. Rossen3,4,5, Jan H. van Zeijl6, Jaap A. Wagenaar 2,7 , and Roosmarijn E.C. Luiken 2 

1. Veterinary and Research Department, Sealcentre Pieterburen, Pieterburen, The Netherlands 

2. Division of Infectious Diseases and Immunology, Utrecht University Faculty of Veterinary Medicine, Utrecht, The Netherlands 

3. Department of Medical Microbiology and Infection Prevention, University Medical Center Groningen, Groningen, The Netherlands 

4. Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT, USA. 

5. Laboratory of Clinical Microbiology and Infectious Disease, Isala hospital, Zwolle, The Netherlands. 

6. Department of Medical Microbiology Friesland and Noordoostpolder, Certe, Leeuwarden, The Netherlands 

7. Wageningen Bioveterinary Research, Lelystad, The Netherlands 

Wat is ie leuk geworden: de zeehondenprint die Studio Ditte speciaal voor ons heeft ontwikkeld. En nog leuker, het kan bij jou thuis aan de muur hangen! Studio Ditte is een bewust merk dat onder andere behang ontwikkelt. Speciaal voor ons hebben ze dit zeehondenbehang ontworpen. En per rol gaat er €5,- naar ons centrum. Daar zijn we natuurlijk erg blij mee, ontzettend bedankt! Het zeehondenbehang is vanaf nu te koop via de webshop van Studio Ditte en via verschillende winkels.

Lees meer over onze samenwerking op het blog van Studio Ditte here. 

Zeehondencentrum Pieterburen heeft de eerste grijze zeehondenpup van dit winterseizoen opgevangen. Het dier kroop gisteravond laat over een weg in Den Helder. Ze is “Hali” genoemd naar de wetenschappelijke naam van haar soort, de grijze zeehond: Halichoerus grypus. De pup bleek de dagen daarvoor al op Texel in observatie te zijn geweest door de zeehondenwachters van Ecomare. De centra roepen – nogmaals – op om de komende weken rust en ruimte te geven aan zeehondenmoeders en hun pups.

Gisteravond rond 19:00 uur kwam er een melding binnen van een zeehondenpup bij het Zeehondencentrum in Pieterburen. De pup was over de dijk gekropen en op de rijweg terecht gekomen. Eenmaal ter plaatse bleek dat het ging om een al gemarkeerde zeehondenpup. De zeehondenwachters van Ecomare hadden de pup al een aantal dagen geobserveerd op Texel. Na navraag bleek de pup inmiddels gewicht te hebben verloren en dat, in combinatie met de locatie, maakte dat de pup werd opgevangen.

De pup is een vrouwtje van minstens 10 dagen oud en weegt nog maar net 15 kilo. Dit is een paar kilo lichter dan wat een pup van haar leeftijd had moeten zijn. Ze is “Hali” genoemd naar de wetenschappelijke naam van haar soort, de grijze zeehond: Halichoerus grypus.

Kortgeleden deed het Zeehondencentrum al de oproep extra alert te zijn rondom zeehonden in deze periode van het jaar. Grijze zeehonden krijgen nu hun pups en moeders hebben maar 2,5 week tijd hun pups te voeden. In die korte periode groeien de pups enorm snel, van 10 kilo bij geboorte naar soms wel 50 kilo als de moeder ze verlaat. Daarom is het essentieel dat zeehondenmoeders en -pups de rust en ruimte krijgen die ze dit jaar nodig hebben.

Pup season in full swing

Is er wel twijfel over de toestand van een zeehond, dan kan er altijd gebeld worden met 144. Zij zullen dan doorverbinden met het centrum dat in dat gebied actief is. De centra sturen dan zeehondenwachters op de melding af om te beoordelen wat er aan de hand is en rust te creëren om de zeehonden heen. Zeehondenwachters zijn actief sinds het in 2020 getekende Seal Agreement. De bedoeling van het akkoord is om zo veel mogelijk problemen voor zeehonden te voorkomen en daarmee het aantal dat in de opvang terecht komt te verlagen.