Intraocular pressure using rebound tonometry in the Galápagos marine iguana (Amblyrhynchus cristatus)

J.E. Christman *, K.J. Lohmann, M. Hirschfeld, J.P. Muñoz-Pérez, J. Garcia, J.A. Hernandez, H. Westermeyer, G.A. Lewbart

The Galápagos marine iguana (Amblyrhynchus cristatus) is the world’s only marine lizard and is capable of swimming and diving to depths of several meters to forage for food. Thus, the physiology of this species must accommodate both terrestrial and underwater environments. Until now, no studies have evaluated ocular health parameters in this species. Free-ranging Galápagos marine iguanas (n=26) were captured in the field. Intraocular pressure (IOP) was measured using rebound tonometry at the beginning and end of the handling period. Tear production was measured using Schirmer tear test (STT) and endodontic absorbent paper point test (EPPT). Baseline physiologic parameters including heart rate and body temperature, as well as morphometric parameters (body weight, total length, snout vent length, hemipene sulcus length), and baseline blood parameters (packed cell volume, total protein, lactate) were evaluated. The mean IOP was 9.4 mm Hg (SD±1.4) and is comparable to other terrestrial iguanid species. Mean STT was 4.1 mm/minute and EPPT was 11.1 mm/minute. The IOP did not vary with snout vent length, total weight, hemipene sulcus length, or between the right and left eye. The IOP was higher at the beginning of handling compared to the end of handling, likely due to immediate stress associated with capture. The IOP did not vary with packed cell volume (PCV), total protein (TP), or lactate. These results represent a first step toward establishing a baseline for ocular health parameters in marine iguanas.

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In 2022, the Galapagos Science Center (GSC) and the broader UNC & USFQ Galapagos Initiative will celebrate its 10th Anniversary. We are proud to announce the World Summit on Island Sustainability scheduled to be held on June 26–30, 2022 at the Galapagos Science Center and the Community Convention Center on San Cristobal Island.

The content of the World Summit will be distributed globally through social media and results documented through papers published in a book written as part of the Galapagos Book Series by Springer Nature and edited by Steve Walsh (UNC) & Carlos Mena (USFQ) as well as Jill Stewart (UNC) and Juan Pablo Muñoz (GSC/USC). The book will be inclusive and accessible by the broader island community including scientists, managers, residents, tourists, and government and non-government organizations.

While the most obvious goal of organizing the World Summit on Island Sustainability is to celebrate the 10th Anniversary of the GSC and the UNC-USFQ Galapagos Initiative, other goals will be addressed through special opportunities created as part of our operational planning of the World Summit.

For instance, we seek to elevate and highlight the Galapagos in the island conservation discourse, seeking to interact with other island networks in more obvious and conspicuous ways to benefit the Galapagos Islands, the UNC-USFQ Galapagos Initiative, and the world. We will seize the opportunity to further develop the I2N2 – International Islands Network-of-Networks. Further, we wish to highlight and emphasize multiple visions of a sustainable future for the Galapagos Islands and we cannot do this alone. Therefore, engaging the Ecuadorian Ministry of Environment, the Ministry of Tourism, the Government Council of Galapagos, the Galapagos National Park, and local Galapagos authorities, including government and non-government organizations and local citizen groups, is imperative.

The Galapagos Science Center on San Cristobal Island, Galapagos

Borrowing from Hawaii’s and Guam’s Green Growth Program and the Global Island Partnership, we wish to examine existing global programs that emphasize island sustainability and their incorporation into life, policies, and circumstances in the Galapagos Islands. We will also seek to enhance our connections with the institutional members of our International Galapagos Science Consortium and expand the Consortium through the recruitment of other member institutions. We will also work to benefit islands and their local communities by working with citizen groups as well as important NGOs who seek to improve the natural conditions in the Galapagos and diminish the impact of the human dimension on the future of Galapagos’ ecosystems.

Lastly, we will use the World Summit to benefit UNC & USFQ and our constituencies through a strong and vibrant communication plan about the World Summit, creating corporate relationships as sponsors, identifying funding goals through donors, and benefiting our study abroad program for student engagement in the Galapagos Islands. We plan to develop and issue a Galapagos Sustainability Communique after the World Summit that includes the vision and insights of all its participants for a sustainable Galapagos with applicability to global island settings.

We are eager to hear your perspective and have you join us at the World Summit on Island Sustainability!