Mangrove Poleward Expansion and Regulation Opportunities

To: Senate Majority Leader Wilton Simpson and Senate Minority Leader Oscar Braynon

From: Kathryn Greene and Will Fletcher-Hill

Subject: Florida Mangroves’ Unexpected Expansion

Date: May 9th, 2018

Introduction

Protecting Florida’s mangroves means protecting Florida’s future. In the past several decades, climate change has decimated mangroves by 35%[1]. In response to climate change, scientists have discovered mangrove trees are growing far beyond their typical range. In 2014, Cavannaugh et al. determined that mangrove ecosystems in Florida were rapidly expanding poleward due to fewer cold snaps, a phenomenon associated with climate change.[2] The Florida State Government will need to tackle this issue in the near future as expanding mangrove forests pose a number of potential issues.[3] For instance, mangrove forests could foster new ecosystems, but could also displace salt marshes at their northern limit.[4] This policy memo evaluates the three most likely policy options available to the Florida State Government: making No Change to current mangrove regulations, Expanding Regulations to protect migrating mangrove forests, and Reducing Regulation to combat poleward expansion. We propose that expanding regulation would be the most effective option for regulating Florida’s mangrove. For all options, this Policy Memo assumes that additional research must be conducted to better understand mangrove expansion and its repercussions. Each option is evaluated based on seven weighted criteria, which address a range of social, economic, political, and technological issues associated with mangrove regulation.

1. Human Health (social)
2. Cost (economic)
3. Effectiveness (technological)
4. Political Feasibility (political)
5. Ecosystem Health (technological)
6. Time (political, economic)
7. Impact on Landowners (social and political)

Each option receives a score from each criterion ranging from 1 to 5 (low, moderately low, moderate, moderately high, and high) which is displayed in Appendix A, where 1 means the option has low benefits for the affected criteria and 5 means the option has high benefits for that criteria. A score of 1 for Cost means that option has a very high financial cost, lowering the overall score. Initial Weighted Scores are calculated using the sum of weighted scores for each criterion. Scores are then multiplied by Certainty Multipliers, decimals representing how certain we are in each score, which results in the Final Weighted Score.

Option 1: No Change in Regulations

Trimming and removal of mangroves has been regulated by the Florida State legislature in an effort to preserve these valuable and beneficial ecosystems.[5] However, current legislature has been ineffective in protecting mangroves from human intervention and does not account for the effects of climate change on mangrove ecology.[6] Approximately 80% of Florida mangroves consisting of Laguncularia racemosa (white mangrove), Rhizophora mangle (red mangrove), and Avicennia germinans (black mangrove) are protected from unregulated trimming and alteration yet there are several weaknesses in current legislature that need to be evaluated.[7]

• The majority of Florida’s mangroves are under some form of government or private ownership. With the decline of mangroves, beneficial ecosystem services such as the reduction of harmful pollutants, storm damage, and erosion would be lost and negatively impact human and ecosystem health.[8] However, mangroves are still subject to removal through dredging and filling and are sacrificed for private riparian rights of view.[9] For these reasons, making no change to current mangrove regulations receives a moderate score for Ecosystem Health and a moderately low score for Human Health (Appendix A).
• Instances where a permit is required to trim mangroves are rare. The state and local government is likely losing revenue from the lack of permit fees, and without a permit, most violations like excessive trimming or removal go undetected.[10] In addition, proper mitigation or restoration of mangroves has proven to be ineffective because mangroves have complex habitat requirements and restoration projects require extensive amount of money and long-term monitoring plans that are typically not enforced.[11] Furthermore, current regulations do not address the poleward expansion of mangroves. For these reasons, making no change to current mangrove regulations receives a moderately low score for both Effectiveness and Cost (Appendix A).
• Property owners have the power to maintain their mangroves, which increases property values, retains their scenic views and justifies their property tax rates. For these reasons, making no change to current mangrove regulations receives a moderately high score for Impact on Landowners (Appendix A).
• No alteration to current mangrove legislation would not require additional time or political feasibility. For these reasons, making no change to current mangrove regulations receives a moderately high score for Time and Political Feasibility (Appendix A).

Option 2: Expanding Mangrove Regulations

Expanding mangrove protections would protect expanding mangrove ecosystems but could prove politically and economically costly. As mangroves expand poleward along the Florida coast, more regions will become legally subject to the Mangrove Trimming and Preservation Act.[12] If mangrove protections are expanded, they must address landowners who have never had to deal with mangroves growing on their property before. One of the historic contentions over mangrove regulation has been that Florida property owners desire the right to trim and/or remove mangroves on their coastal property to improve the view.[13] Effectively defending mangrove expansion would require expanding state and local oversight capabilities for protecting mangroves under existing laws, delegating more regions as “public lands set aside for conservation or preservation,”[14] and substantially altering mitigation requirements.[15]

• Expanding mangrove ecosystems around Florida would provide additional protection against hurricanes and other storm impacts.[16] For this reason, expanding regulations receives a high score for Human Health (Appendix A).
• Protecting mangrove expansion would require substantially more government resources, driving up the cost. On the flipside, more mangroves would save money in the long term by reducing hurricane damage. Many local government offices can issue permits for mangrove trimming and/or removal and may over-issue such permits since a) permits can be a source of local revenue and b) many communities may want to resist mangrove incursions.[17] To prevent this, permit issuing regulations would need to become more stringent and state-level oversight would need to increase. For these reasons, expanding regulations receives a moderate score for Cost (Appendix A).
• Since coastal Florida landowners would especially be affected by expanding regulations, such actions would likely be politically undesirable for many state representatives.[18] For this reason, expanding regulations receives moderately low scores for Impact on Landowners and Political Feasibility (Appendix A).
• Effectively expanding regulations might disrupt some ecosystems dependent on salt marshes[19] but would drastically increase the carbon storage potential of those regions. Mangrove ecosystems can absorb and process significantly more CO₂ than their salt marsh counterparts.[20] The rate of mangrove expansion is also relatively rapid.[21] For these reasons, expanding regulations receives moderately high scores for both Ecosystem Health and Effectiveness, and a moderate score for Time (Appendix A).

Option 3: Reducing Mangrove Regulations

Reducing mangrove protections would be the best tool for combating poleward mangrove expansion but could also be used to justify further mangrove clearing in the long run.  Reducing mangrove regulations, in this case, would allow individual property owners to easily acquire permits to trim and/or remove mangroves on their property, likely by lowering the requirements and/or cost of getting a permit. The legal history of mangrove regulation demonstrates that Florida landowners would find this to be an attractive path to pursue, but history also suggests that such a solution could inspire Florida lawmakers to loosen restrictions in southern mangroves as well, causing state-wide degradation.[22]

• Loosening mangrove regulations would pose a threat to human health since it degrades Florida’s natural defenses against hurricanes and other storm impacts.[23] For this reason, reducing regulations receives a low score for Human Health (Appendix A).
• Loosening mangrove regulation by making permits cheaper would mean less revenue for local governments, which would be costly.[24] That cost might be balanced out, however, as the price of coastal property increases with fewer regulations.[25] For these reasons, reducing regulations receives a moderately high score for Cost (Appendix A).
• Reducing regulations would be very popular with coastal Florida landowners, making state and local representatives more likely to support them.[26] For these reasons, reducing regulations receives a high score for Impact on Landowners and a moderately high score for Political Feasibility (Appendix A).
• Reducing regulations would damage mangrove ecosystems, as it would allow more coastal Florida landowners to take mangrove removal into their own hands. On the contrary, however, removing mangroves would help preserve salt marshes.[27] For these reasons, reducing regulations receives a moderately low score for Ecosystem Health, a moderately high score for Effectiveness, and a moderate score for Time (Appendix A).

Conclusion

Based on the analysis, increasing regulations to create more protection for expanding mangrove ecosystems would be the best strategy, especially in the context of climate change. This Policy Memo therefore recommends that the Florida state government increase state oversight of permit issuing and revise its ineffective mitigation policies. Despite the potential backlash from landowners and political figures, this option would ensure the health of ecological and human communities for the long-term. By expanding state and local oversight capabilities to include more regions, protection of mangroves would increase under current legislation. Along with the proposed options, more scientific research would only increase our understanding of mangrove ecology and improve management strategies.

Appendices

Appendix A: Table of Scores for Options by Criterion, scored 1 (low) to 5 (high).  A score of 5 is the most beneficial for that criterion.  Initial Weighted Scores are calculated using the sum of the weighted score for each criterion.  Final Weighted Scores are calculated by multiplying the Initial Weighted Score with its respective Certainty Multiplier.

Bibliography

Florida State Legislature. 1996 Mangrove Trimming & Preservation Act. 403.9321-403.9333. Florida Statutes, 1996. https://floridadep.gov/sites/default/files/mtpa96_0.pdf.

Cavanaugh, Kyle C., James R. Kellner, Alexander J. Forde, Daniel S. Gruner, John D. Parker, Wilfrid Rodriguez, and Ilka C. Feller. “Poleward Expansion of Mangroves Is a Threshold Response to Decreased Frequency of Extreme Cold Events.” Proceedings of the National Academy of Sciences 111, no. 2 (2014): 723–27. https://doi.org/10.1073/pnas.1315800111.

Doughty, Cheryl L., J. Adam Langley, Wayne S. Walker, Ilka C. Feller, Ronald Schaub, Samantha K. Chapman. “Mangrove Range Expansion Rapidly Increases Coastal Wetland Carbon Storage.” Estuaries and Coasts 39, no. 2 (2016): 385–96. https://doi.org/10.1007/s12237-015-9993-8

Fisher, Kellyalexis. “Man Let ’em Grow: The State of Florida Mangrove Laws.” The Florida Bar Journal Volume LXXII, no. 5 (1998). https://www.floridabar.org/news/tfb-journal/?durl=/divcom%2Fjn%2Fjnjournal01%2Ensf%2FAuthor%2FDBAE001D7B30B37885256ADB005D61D5.

Florida Coastal Office. “Florida Coastal Management Program Guide: A Guide to the Federally Approved Florida Coastal Management Program.” Department of Environmental Protection. 2017. https://floridadep.gov/sites/default/files/FCMP-Program-Guide-2017_0.pdf.

Gillis, Justin. “Spared Winter Freeze, Florida’s Mangroves Are Marching North,” New York Times, December 30, 2013.  https://www.nytimes.com/2013/12/31/science/without-winter-freezes-mangroves-are-marching-north-scientists-say.html?pagewanted=all

Jennerjahn, T. C., E. Gilman, K.W. Krauss, L.D. Lacerda, I. Nordhaus, and E. Wolanski. “Mangrove Ecosystems under Climate Change.” In Mangrove Ecosystems: A Global Biogeographic Perspective, 211–44. Cham: Springer, 2017. https://doi.org/10.1007/978-3-319-62206-4_7.

Kimbel, Ericson P. “The Ecological and Economic Failures of Florida’s Mangrove Regulatory Scheme.” Ocean and Coastal Law Journal 5, no. 1 (2000): 23-44. https://digitalcommons.mainelaw.maine.edu/oclj/vol5/iss1/3.

Rivera-Monroy, Victor H., Shing Yip Lee, Erik Kristensen, and Robert R. Twilley. Mangrove Ecosystems: A Global Biogeographic Perspective. Cham: Springer International Publishing, 2017. https://doi.org/10.1007/978-3-319-62206-4.

Saintilan, Neil, Nicholas C. Wilson, Kerrylee Rogers, Anusha Rajkaran, and Ken W. Krauss. “Mangrove Expansion and Salt Marsh Decline at Mangrove Poleward Limits.” Global Change Biology 20, no. 1 (2014): 147–57. https://doi.org/10.1111/gcb.12341.

Waymer. Jim. “Could Mangrove Northern Expansion Temper Global Warming?” Florida Today, January 14, 2017. https://www.floridatoday.com/story/news/local/environment/2017/01/14/could-mangrove-northern-expansion-temper-global-warming/94736686/.

On our honor we have neither given nor received unauthorized information regarding this work, we have followed and will continue to observe all regulations regarding it, and we are unaware of any violation of the Honor Code by others.

Endnotes

[1] Jim Waymer. “Could Mangrove Northern Expansion Temper Global Warming?” Florida Today, (January 14, 2017). https://www.floridatoday.com/story/news/local/environment/2017/01/14/could-mangrove-northern-expansion-temper-global-warming/94736686/.

[2] Kyle C. Cavanaugh et al., “Poleward Expansion of Mangroves Is a Threshold Response to Decreased Frequency of Extreme Cold Events,” Proceedings of the National Academy of Sciences 111, no. 2 (January 14, 2014): 723–27, https://doi.org/10.1073/pnas.1315800111.

[3] Victor H. Rivera-Monroy et al., eds., Mangrove Ecosystems: A Global Biogeographic Perspective (Cham: Springer International Publishing, 2017), https://doi.org/10.1007/978-3-319-62206-4.

[4] Cheryl L. Doughty et al., “Mangrove Range Expansion Rapidly Increases Coastal Wetland Carbon Storage,” Estuaries and Coasts 39, no. 2 (March 1, 2016): 385–96, https://doi.org/10.1007/s12237-015-9993-8.

[5] Florida State Legislature, “1996 Mangrove Trimming & Preservation Act,” 403.9321-403.9333 403.9321 § (1996), https://floridadep.gov/water/submerged-lands-environmental-resources-coordination/documents/mangrove-trimming-and, 403.9325(6).

[6] Ericson Kimbel, “The Ecological And Economic Failures Of Florida’s Mangrove Regulatory Scheme,” Ocean and Coastal Law Journal 5, no. 1 (May 19, 2016), https://digitalcommons.mainelaw.maine.edu/oclj/vol5/iss1/3.

[7] Kellyalexis Fisher, “Man Let ’em Grow: The State of Florida Mangrove Laws,” The Florida Bar Journal Volume LXXII, no. No. 5 (May 1998), https://www.floridabar.org/news/tfb-journal/?durl=/divcom%2Fjn%2Fjnjournal01%2Ensf%2FAuthor%2FDBAE001D7B30B37885256ADB005D61D5.

[8] T. C. Jennerjahn et al., “Mangrove Ecosystems under Climate Change,” in Mangrove Ecosystems: A Global Biogeographic Perspective (Springer, Cham, 2017), 211–44, https://doi.org/10.1007/978-3-319-62206-4_7.

[9] Ericson Kimbel, “The Ecological And Economic Failures Of Florida’s Mangrove Regulatory Scheme.”

[10] Kellyalexis Fisher, “Man Let ’em Grow: The State of Florida Mangrove Laws.”

[11] Ericson Kimbel, “The Ecological And Economic Failures Of Florida’s Mangrove Regulatory Scheme.”

[12] Florida State Legislature, “1996 Mangrove Trimming & Preservation Act.”

[13] Kellyalexis Fisher, “Man Let ’em Grow: The State of Florida Mangrove Laws.”

[14] Florida State Legislature, “1996 Mangrove Trimming & Preservation Act.”

[15] Ericson Kimbel, “The Ecological And Economic Failures Of Florida’s Mangrove Regulatory Scheme.”

[16] Florida Coastal Office, “Florida Coastal Management Program Guide: A Guide to the Federally Approved Florida Coastal Management Program” (Department of Environmental Protection, October 11, 2017), https://floridadep.gov/sites/default/files/FCMP-Program-Guide-2017_0.pdf.

[17] Florida Coastal Office, “Florida Coastal Management Program Guide: A Guide to the Federally Approved Florida Coastal Management Program.”

[18] Kellyalexis Fisher, “Man Let ’em Grow: The State of Florida Mangrove Laws.”

[19] Neil Saintilan et al., “Mangrove Expansion and Salt Marsh Decline at Mangrove Poleward Limits,” Global Change Biology 20, no. 1 (January 1, 2014): 147–57, https://doi.org/10.1111/gcb.12341.

[20] Doughty et al., “Mangrove Range Expansion Rapidly Increases Coastal Wetland Carbon Storage.”

[21] Doughty et al., “Mangrove Range Expansion Rapidly Increases Coastal Wetland Carbon Storage.”

[22] Kellyalexis Fisher, “Man Let ’em Grow: The State of Florida Mangrove Laws.”

[23] Florida Coastal Office, “Florida Coastal Management Program Guide: A Guide to the Federally Approved Florida Coastal Management Program.”

[24] Florida Coastal Office, “Florida Coastal Management Program Guide: A Guide to the Federally Approved Florida Coastal Management Program.”

[25] Kellyalexis Fisher, “Man Let ’em Grow: The State of Florida Mangrove Laws.”

[26] Kellyalexis Fisher, “Man Let ’em Grow: The State of Florida Mangrove Laws.”

[27] Justin Gillis, “Spared Winter Freeze, Florida’s Mangroves Are Marching North,” New York Times, December 30, 2013, http://www.nytimes.com/2013/12/31/science/without-winter-freezes-mangroves-are-marching-north-scientists-say.html.