In a study done from 1995 to 1997 off the Northwestern coast of Australia, scientists found that whale sharks tolerance for divers and swimmers decreased. The whale sharks showed an increase in behaviors over the course of the study, such as diving, porpoising, banking, and eye rolling that are associated with distress and attempt to avoid the diver. The average time the whale sharks spent with the divers in 1995 was 19.3 minutes, but in 1997 the average time the whale sharks spent with the divers was 9.5 minutes. There was also an increase in recorded behaviors from 56% of the sharks showing any sort of diving, porpoising, eye rolling or banking in 1995 to 70.7% in 1997. Some whale sharks were also observed to have scars that were consistent with being stuck by a boat. Environmental hazards
The industrialization, urbanization and agricultural practices of human society are having a serious impact on the environment. Ecotourism is now also considered to be playing a role in environmental depletion including deforestation, disruption of ecological life systems and various forms of pollution, all of which contribute to environmental degradation. For example, the number of motor vehicles crossing a park increases as tour drivers search for rare species. The number of roads disrupts the grass cover, which has serious consequences on plant and animal species. These areas also have a higher rate of disturbances and invasive species due to increasing traffic off of the beaten path into new, undiscovered areas.
Ankyloblepharon is defined as the adhesion of the edges of the upper eyelid with the lower eyelid. Ankyloblepharon must be differentiated from blepharophimosis, in which palpebral aperture is reduced and there is telecanthus, but the eyelid margins are normal. Another condition similar to ankyloblepharon is symblepharon, in which the palpebral conjunctiva is attached to the bulbar conjunctiva. Recognition of ankyloblepharon necessitates systemic examination to detect associated abnormalities such as genitourinary and cardiac abnormalities and syndactyly. Presentation
Complication
The main complication of congenital ankyloblepharon is amblyopia. Timely separation of the eyelids is very important to avoid the development of occlusion amblyopia. Etiology
Ankyloblepharon may be congenital or acquired. The most common type is congenital.Clinically, ankyloblepharon may be complete, partial, or interrupted. Complete ankyloblepharon is when the eyelids are fused throughout the lid margins. In the partial form, they are joined at one or more points. The interrupted form is also known as ankyloblepharon filiforme adnatum (AFA). Congenital ankyloblepharon
During fetal development, eyelid margins remain fused until the fifth gestational month, and may not be completely separated until the seventh month of gestation. Congenital ankyloblepharon occurs when the lid margins fail to separate at birth. The exact etiology of this condition is unknown. The currently accepted theory is that this condition is due to temporary epithelial arrest and rapid mesenchymal proliferation, allowing union of eyelids at abnormal positions.