old_contents: from rest_framework import serializers
  from api.models import Element, ObservationType, Source, AuVElm
  
  
  class ElementSerializer(serializers.ModelSerializer):
      alt_scientific_names = serializers.CharField(read_only=True)
  
      class Meta:
          model = Element
          fields = (
              'id',
              'scientific_name',
              'alt_scientific_names',
              'common_name',
              'taxonomic_group',
              'endemic',
              'vulnerable',
              'listed',
          )
  
  class ObservationTypeSerializer(serializers.ModelSerializer):
      class Meta:
          model = ObservationType
          fields = (
              'name',
              'range_obs',
              'current_other',
              'observation_group',
          )
  
  class SourceSerializer(serializers.ModelSerializer):
      class Meta:
          model = Source
          fields = (
              'name',
              'citation',
              'weblink',
          )
  
  class AuVElmSerializer(serializers.ModelSerializer):
      element = ElementSerializer(read_only=True)
      observation_type = ObservationTypeSerializer(read_only=True)
      source = SourceSerializer(read_only=True)
  
      class Meta:
          model = AuVElm
          fields = (
              'element',
              'huc_12',
              'observation_type',
              'source',
              'frequency',
              'sum_amount',
          )
  
  class SpeciesSerializer(serializers.BaseSerializer):
      def to_representation(self, obj):
          return {
              obj.id: {
                  'scientific_name': obj.scientific_name,
                  'alt_scientific_names': obj.alt_scientific_names(),
                  'common_name': obj.common_name,
                  'taxonomic_group': obj.taxonomic_group,
                  'endemic': obj.endemic,
                  'vulnerable': obj.vulnerable,
                  'listed': obj.listed,
              }
          }
  
new_contents: from rest_framework import serializers
  from api.models import Element, ObservationType, Source, AuVElm
  
  
  class ElementSerializer(serializers.ModelSerializer):
      class Meta:
          model = Element
          fields = (
              'id',
              'scientific_name',
              'alt_scientific_names',
              'common_name',
              'taxonomic_group',
              'endemic',
              'vulnerable',
              'listed',
          )
  
  class ObservationTypeSerializer(serializers.ModelSerializer):
      class Meta:
          model = ObservationType
          fields = (
              'name',
              'range_obs',
              'current_other',
              'observation_group',
          )
  
  class SourceSerializer(serializers.ModelSerializer):
      class Meta:
          model = Source
          fields = (
              'name',
              'citation',
              'weblink',
          )
  
  class AuVElmSerializer(serializers.ModelSerializer):
      element = ElementSerializer(read_only=True)
      observation_type = ObservationTypeSerializer(read_only=True)
      source = SourceSerializer(read_only=True)
  
      class Meta:
          model = AuVElm
          fields = (
              'element',
              'huc_12',
              'observation_type',
              'source',
              'frequency',
              'sum_amount',
          )
  
  class SpeciesSerializer(serializers.BaseSerializer):
      def to_representation(self, obj):
          return {
              obj.id: {
                  'scientific_name': obj.scientific_name,
                  'alt_scientific_names': obj.alt_scientific_names(),
                  'common_name': obj.common_name,
                  'taxonomic_group': obj.taxonomic_group,
                  'endemic': obj.endemic,
                  'vulnerable': obj.vulnerable,
                  'listed': obj.listed,
              }
          }
  
subject: use alt_scientific_names aggregator