Initially outdoor light ordinances were adopted by communities with research observatories at the urging of astronomers. But star-gazing is not the only reason for regulating night lighting. Many of Florida's oceanfront communities have adopted lighting codes to protect the nesting sea turtles along beaches. Sea turtle hatchlings instinctively head toward light. Before electric lighting, bioluminescence and the reflection of the moon on the water made the ocean brighter than the land. But due to light pollution, hatchlings often head inland. The strict limits on street lighting on Sanibel Island aim to remedy the imbalance between the unnatural brightness of the shoreline and the natural bioluminescence of the sea.

The four sections of Sanibel Island's zoning statutes pertaining to with outdoor lighting are listed below.

Section I.E.14 Outdoor Lighting

All outdoor lighting shall be installed in such a manner and be so shielded that the cone of light shall fall, substantially, within the perimeter of the property, and where applicable, landward of the Coastal Construction Control Line. Through the use of shielding and limitations upon intensity, ambient light traveling outward and upward, producing a sky glow, shall be reduced to the greatest extent possible without unduly interfering with the intent and purpose of the outside lighting in the first instance. The lighting of beach walkovers is permitted seaward of the Coastal Construction Control Line but only mushroom-type light fixtures, which direct the light downward, shall be permitted. Such lighting shall also meet the following requirements:

a. Such fixtures shall be installed at least twenty-five (25) feet apart and not more than one (1) foot above the surface of the walkover.

b. Illumination shall be limited to twenty-five (25) watts through the use of a twenty-five-watt yellow bulb.

Section I.E.18 (part v)

v. Illuminated graphics. Illuminated street graphics, in addition to conforming to all other requirements of this section, shall be shielded in such a manner so that no direct source of light is cast into streets or residential properties. Illuminated street graphics shall not interfere with pedestrian or motorist vision. Said illumination shall not be reflective or phosphorescent and shall be in a steady nonfluctuating or nonundulating manner and placed in a manner that will not create a nuisance to other premises or interfere with traffic.

Section I.E.29 (part i)

i. Glare. All lighting shall be so hooded or shielded as to reflect the light in such a manner that no illumination source or glare creates a nuisance to any adjoining property or unreasonably interferes with the lawful use and enjoyment of any adjoining property. Such lighting shall not under any circumstances exceed a maximum intensity of twenty-five (25) footcandles at ground level.

And, the from the Code of Ordinances of the City of Sanibel, Florida, Part II Code of Ordinances, Chapter 13 Offenses and Miscellaneous Provisions:

Sec. 13-8. Outside lighting which disturbs neighboring residences.

(a) Deemed nuisance; prohibited. Outside lighting such as lamps, bulbs, lights and all other devices for producing artificial light which shine or reflect light onto or into a neighboring residence so as to annoy or disturb the persons inhabiting such neighboring residence is hereby declared to be a nuisance and is unlawful and prohibited. Investigation and enforcement by the city of violations of this ordinance shall be only upon written complaint signed and submitted by the aggrieved complaining party.

(b) Penalties. Any person causing, maintaining, suffering or allowing the above described nuisance shall be subject to the penalties and enforcement procedures set forth in section 1-9 of this Code of Ordinances.

(Ord. No. 80-25, §§ 1, 2, 9-10-80)

Source: International Dark-Sky Assoication